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Christian Ethics — Doing God’s Will from the Heart

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The subject for this year’s conference is Christian ethics. Ethics are principles of conduct. They have to do with right and wrong, and, of course, Christian ethics are based on Scripture. We can say that they are Biblical principles of right and wrong. Over the next couple of days, I’ll be addressing a lot of subjects. Unfortunately, I will be able to address each of them only briefly. If you have any questions beyond what I say, please don’t hesitate to ask.

As we begin, we must first recognize that every decision we make is an ethical decision. But knowing what to do is not always easy. We want to do God’s will, but how do we know what God’s will is in a given situation? Should I go to college? If so, which one and what should I study? Should I marry Barbara or Margaret? Should I buy a home or continue to rent? Should my wife and I have three children or fourteen? Should I take a new job or stick with the old one?

You see, you can ask this question about everything you do. When people want to know God’s will, most of the time they are concerned about the big decisions in their lives (marriage, family and career). But actually it relates to little decisions, too. Is it God’s will for you to buy peppermint or spearmint gum? If you really want to do God’s will, you have to do it in the little things just as much as the big ones. Otherwise, you’re only doing part of God’s will.

But what do people really mean when they want to know God’s will. More often than not, they mean that God has a wonderful plan for their lives, and they want a preview of that plan so that they can know what choices God will bless. Finding God’s will not usually their attempt to please God, but rather their effort to find a way to make God please them.

The Will of God

Does this mean, then, that it is inappropriate to talk about doing God’s will? Of course not. In fact, there are several passages in Scripture that use this very phrase. Jesus said, For whosoever shall do the will of God, the same is my brother, and my sister, and mother (Mark 3:35). Obviously, we cannot do the will of God unless we know what the will of God is. Similarly Ephesians 6:6 adds that we are to serve Christ by doing the will of God from the heart. The will of God is also mentioned in our text.

Before we look at our text, however, we should note that the phrase “the will of God” has two very distinct meanings in Scripture.

Sometimes it refers to God’s decree, i.e., his all-encompassing plan for the entire universe. It refers to those things that most certainly will come to pass. After Nebuchadnezzar’s reason returned to him, he proclaimed that God doeth according to his will in the army of heaven, and among the inhabitants of the earth (Dan. 4:35). This means that everything in creation follows his plan. Paul stated this principle even more directly in the New Testament. He wrote that God worketh all things after the counsel of his own will (Eph. 1:11).

However, this cannot be what the phrase means when we talk about DOING the will of God. Why? There are several reasons.

First, if doing the will of God simply means that we follow his plan, then everyone — believer and unbeliever alike — does God’s will always and infallibly. It has to be this way, since God’s will determines every event that takes place, including sin. The crucifixion of Christ is, without a doubt, the greatest sin ever committed, but have you ever noticed that the sermons in Acts emphasize repeatedly that even it was the product of the determinate counsel and foreknowledge of God (Acts 2:23; cf. Acts 3:18; 4:28)? The Belgic Confession recognizes this when it affirms that God orders and executes his perfect plan even “when devils and wicked men act unjustly” (Art. 13). The will of God’s decree is inescapable.

Second, if doing the will of God means that we follow his plan and following his plan requires us to know his plan in advance, then the whole idea of doing God’s will runs counter to other Scriptural principles. For example, Deuteronomy 29:29 says that, unless God reveals the future, it is not our business to know it. Moses wrote, The secret things belong unto the LORD our God: but those things which are revealed belong to us and to our children for ever, that we may do all the words of this law. Nowhere does the Bible encourage believers to find out their biographies in advance. And since God has chosen not to give us this information, searching for it can end only in frustra­tion.

But “the will of God” also has a second meaning in Scripture. In other places, it’s a synonym for keeping God’s commandments. We find this meaning, for example, in I John 2:17, where doing the will of God is contrasted specifically with worldliness and sin. John assured his readers that the world and all of its lusts will pass away, but he that doeth the will of God abideth for ever.

This gives us a completely different perspective on doing God’s will. Instead of looking into a crystal ball to determine what actions God will bless, we turn to the pages of Scripture to learn what kinds of behavior please God. Doing what is morally pleasing to God is admirable. It flows out of a heart that has been re-created in the image of Christ by the irresistible grace of God.

Avoiding Fornication

We’ve spent a fair amount of time looking at the will of God today because that’s what our text is about. Paul begins by saying, For this is the will of God, even your sanctification. In view of the fact that he mentioned the commandments of Christ in the verse preceding our text and that the remainder of our text rehearses a few of those commandments, how can we come to any conclusion except that doing the will of God means that we submit ourselves heart and soul to God’s law?

The first commandment in the list before us comes at the end of verse 3. The Word of God instructs believers to abstain from fornication (v. 3).

The fact that fornication heads the list probably indicates that it was a rather serious problem in Thessalonica at the time Paul wrote to the church. This shouldn’t surprise us. Thessalonica was a bustling seaport, with sailors coming and going all the time. Sailors in the first century were not much different than sailors today. But the fact is that fornication was widespread in the first century, just as it is today. Christ condemned fornication in Matthew 15:19. He said that it flows out of an evil heart. Paul also denounced it numerous times throughout his epistles, but especially in I Corinthians. I Corinthians 6:18 says, Flee fornication. This comes after the statement a few verses earlier that unrepentant fornicators will not inherit the kingdom of God (vv. 9–10). In Corinth, fornication was so bad that a man even slept with his stepmother (I Cor. 5:1–5). There is no indication in I Thessalonians that the problem had sunk to this level, but it still had to be addressed.

Sources outside of the Bible confirm the prevalence of fornication and other sexual sins in the New Testament world. One commentator notes that “anyone who has seen a collection of Greek pottery will know that Playboy magazine is more restrained.” Another says that it was simply assumed in the first century that men would look outside their marriages for the satisfaction of their desires; absti­nence was considered too unnatural.

The sexual revolution of the 70s minimized the importance of the seventh commandment and equated inhibitions with an unenlightened past. Whether the Lord sent AIDS specifically as a punish­ment for homosexuality and other gross violations of the seventh commandment is hard to say, but for a short time the fear of AIDS did restore a little self-restraint. As AIDS has become less of a concern through condom distribution and the development of certain drugs, and as postmodern philosophy has removed the discussion of meaning and purpose from the table, it seems that sexual sins are again on the rise. Sadly, a lot of this kind of thinking has entered into the church.

But what did Paul say? He said that it is God’s will for you to avoid fornication altogether. Don’t toy with it! Don’t convince yourself that it’s okay to develop inappropriate relationships with the opposite sex as long as you don’t actually commit the act of fornication. Just stay away from it! Keep it as far from you as possible!

Jay Adams gives a good illustration of what this means. Let’s say that a man is afraid of falling off a cliff. As he goes to work everyday, he passes by the same cliff and everyday the cliff terrorizes him. What should he do? The easiest solution would be to find another way to work. Instead of walking along the edge of the cliff, he should take a safer inland route.

The fifth chapter of Proverbs says that the lips of a strange woman drop as an honeycomb, and her mouth is smoother than oil (v. 3). It’s a simple fact that, if the temptation to immorality were not attractive, it would not be a temptation. Remember that the ways of a seductress, though perfumed with the finest fragrances, still lead to death and hell (v. 5). That’s why Solomon wrote, Remove thy way far from her, and come not nigh the door of her house (v. 8). In other words, don’t go anywhere near her. Avoid her at all costs!


Not only must we abstain from fornication, but Paul also says that every one of you should know how to possess his vessel in sanctification and honour.

Knowing how to possess your vessel is not just an intellectual exercise. It certainly begins with the intellect. You have to understand the process of maintaining the holiness of your vessel. But that’s not all that God wills for you. He wants you to guard and keep your vessel, and he wants you to delight in doing so. You should make the holiness of your vessel one of your chief priorities, and you should enjoy doing so.

But what does Paul mean when he says that we should possess our vessels in sanctification and honor? The answer to this will depend on how you understand two words: possess and vessel.

We’ll take the second word first. Some commentators have the opinion that the word vessel (σκεῦος) in verse 4 means a man’s wife. In support of this notion, they argue that the verb possess (κτᾶσθαι) usually, though not always, means acquire. Thus, they say, sexual immorality can be avoided by acquiring a wife. While it is true that marriage tends to reduce immorality, it will never keep a heart full of lust from straying. Something more is needed.

There are several reasons for rejecting this view. First, it seems rather peculiar to refer to a man’s wife as his vessel or instrument. I Peter 3:7 says that the wife is a weaker vessel, but there she is the Holy Spirit’s vessel and not her husband’s. A husband, according to I Corinthians 11:7, should honor his wife as his glory. Secondly, our text is addressed to every one of you (v. 4), i.e., to women as well as to men. Men are not the only ones who commit fornication, nor are they the only ones who should possess their vessels in sanctification and honor. Our moral purity is something that each and every one of us should guard.

It seems better, therefore, to take the word vessel as a metaphor for the human body. You are responsible to possess and control your bodies in such a way that you avoid fornication. By the grace of God you can do so.

The temptation to sexual sin is especially strong among teenagers and young adults. As boys and girls mature into men and women, at times they seem to be nothing but flaming hormones. And this is precisely when they need, but would rather not have, parental guidance. We can reduce conflicts, however, by teaching our children when they are young why courtship is a much better than casual dating.

The whole point of dating is to allow young people to find their own mates. But there are two problems with this. First, young people are not the best judges of character. Especially when someone of the opposite sex catches their attention, they become blind to that person’s faults. Parents need to play an active role in steering their children from potential marital disasters and towards relationships that please the Lord Jesus Christ. Second, since dating encourages young people to find their own mates, it also implies that they will do so privately, which provides opportunity for fornication.

I’m not suggesting that parents choose spouses for their children. In fact, I would be opposed to that. When two people get married, they make vows to each other, and they have to be able to do without reservation. But I am suggesting that parents need to monitor their children’s relationships, especially those that may lead to marriage, and they must chaperone them to protect them from slipping into sin. This is what we mean by courtship.

In the Bible, courtship is very simple. It has one purpose — marriage. Our sons take wives either by themselves or through their parents, but our daughters are given in marriage (Deut. 7:3). That’s not sexist, but Biblical. It has to do with the different roles that men and women play in the home, society and the church.

Honesty and Integrity

Another aspect of the will of God is that no man go beyond and defraud his brother in any matter (v. 6). Here the translation uses a phrase that may have been common in the seventeenth century but is not used at all today. To go beyond someone means to take advantage of him. Thus, going beyond and defrauding a brother involves the violation of three of the Ten Commandments. First, it involves covetousness. The individual wants something that doesn’t belong to him and he plans to get it in an unlawful way. Second, it involves deception and falsehood. This is how he acquires the thing he wants. And finally, the end result is theft.

It might seem strange, though, that Paul discouraged defrauding a Christian brother but said nothing at all about cheating unbelievers. Does this mean that we do not have the same ethical obligation toward those outside the pale of the Christian faith as toward those in the church? Is it okay to sin against unbelievers? Of course not! Lest someone think that such behavior might be acceptable, remember that there are no limitations to these commandments elsewhere. The only reason that Paul mentioned our brothers here is to emphasize that cheating and defrauding fellow believers is an especially heinous crime.

Reasons for Doing the Will of God

In verses 6 and 7, Paul gave two reasons why fornication, lying and stealing should be shunned. His reasons help us understand the necessity of unquestioned obedience.

Paul’s first reason, stated at the end of verse 6, is that God punishes wicked men. He wrote, Because that the Lord is the avenger of all such, as we also have forewarned you and testified. II Thessalonians 1:8 adds that Jesus, when he returns in the company of his angels, will take vengeance on everyone who does not obey the gospel of Jesus Christ. Ven­geance often carries the connotation of being extreme, excessive, and usually unjust. But for the Lord vengeance is neither more nor less than perfect justice.

A second reason is given in verse 7. God has called us to live in holiness. We have already come upon the word sanctification twice (vv. 3 and 4) and this is exactly the same word as holiness (ἁγιασμός). It means that you have been dedicated and set apart to the service of God. You are not allowed to fulfill your own lust and desires. Patterning your lives on the world’s philosophies and opinions is not acceptable. Such things are common and unclean. God has summoned you to something far greater. And, since the call is from God, those who reject it also reject God (v. 8). As a seal of the divine call to holiness, God had also given the Thessalonians (and all other Christians as well) the gift of his Holy Spirit.

Perhaps a third reason is implied in verse 8, though it is not as directly stated as the first two. The word order in the Greek suggests an emphasis on the word Holy in Holy Spirit. This probably means that every sin challenges the holiness of the third person of the Trinity. So, it’s not just your reputation that is at stake. God’s is, too. You must never allow either one to suffer damage. You must never allow the world to question the holiness of the Spirit of grace.

Another Example: Marrying in the Lord

For a few minute, I want us to look at a specific example of how to discern God’s will, viz., marrying in the Lord. Paul speaks to this matter in II Corinthians 6:11–18. The most common application of our text relates it to marriage, but Paul did not even mention marriage. He chose, rather, to speak more broadly so that you, as God’s people, might devote yourselves wholeheartedly to the Lord Jesus Christ. This passage tells you one of the most basic things that you need to know in order to make good use of the Spirit’s sanctifying grace.

The principle here is soundly rooted in the Old Testament. Leviticus 19:19 says, Thou shalt not let thy cattle gender with a diverse kind: thou shalt not sow thy field with mingled seed: neither shall a garment mingled of linen and woollen come upon thee. Deuteronomy 22:10 adds, Thou shalt not plow with an ox and an ass together. God gave these commandments to cultivate a sense of purity among the people of God. They were to be so pure that they, unlike the surrounding nations, would keep even their cattle, their seed and their fabrics separate. This was to teach them that there should be no mixture in their service of God.

Based on these precepts, Paul instructed the Corinthians not to be (μὴ γίνεσθε; lit. “do not continue to become”) unequally yoked together with unbelievers. The context suggests that he had something very specific in mind, viz., a believer pursuing a binding covenant of fellowship with an unbeliever. Note the unmistakable references to the covenant throughout this passage, but especially in verses 16–18. In other words, this passage does not prohibit you from having a casual friendship with your unbelieving neighbors (in most cases, you’ll never win them to Christ unless you do so), nor does it bar you from hiring an unbeliever to clean your carpets or repair your microwave. These relationships are either not binding or they are not covenants of fellowship. But this passage does forbid you to establish a binding relationship with an unbeliever in which both of you pledge mutual responsible to each other and for each other. Two situations that come to mind right away are business partnerships and marriage, although it appears that in our text Paul was specifically concerned about religious covenants. In his first epistle he expressed concern about the idolatry of the Corinthians (I Cor. 10:14), and later in this epistle he warned them of the dangers of fellowshipping with false apostles (II Cor. 11:1–4). He wanted them to stop forming such relationships so that they could devote themselves wholly to the service of the Lord Jesus Christ.

The Word of God instructs you not to become unequally yoked together with unbelievers. You should not conclude from this that there is such a thing as an equal yoke in a mixed relationship. The Greek word (ἑτεροζυγοῦντες) used here doesn’t have anything to do with inequality. It literally forbids putting two different kinds of animals in the same yoke. In other words, it repeats the commandment given in Deuteronomy 22:10, which we looked at earlier. The law of God forbad plowing with an ox and an ass yoked together because that inevitably involved an unequal relationship. The ox not only did all the work, but also had to drag the ass around, which only made his work that much harder. But Paul’s reason for repeating this commandment has nothing to do with animals. It’s about human relationships. When a believer is yoked together with an unbeliever in a binding covenant of fellowship, this is itself an unequal relationship that prevents the believer from serving serving the Lord to his fullest potential. He always has to combat the evil inclinations and influences of the unbeliever.

Paul brings this to our attention by asking a series of rhetorical questions that were designed to show the vast gulf between the kingdom of Jesus Christ and the kingdom of Satan. In fact, they are at war with one another. Christ’s kingdom is characterized by righteousness, light (truth), Christ as king, belief of the truth, and the worship and service of the true God. Satan’s kingdom is the opposite of these in every way. It’s distinguished by unrighteousness, darkness (falsehood), Belial (which literally signifies a worthless person, the devil himself being the most worthless, in contrast to the glory of Christ), infidelity and devotion to powerless idols.

As the people of God, it is not within your prerogative to yoke yourselves together in such a relationship.

The Marriage Covenant

This applies specifically to marriage. Just as the Old Testament prohibited mixing together various animals, seeds and fabrics, so it also proscribed intermarriage with unbelievers. Deuteronomy 7:3 says, Neither shalt thou make marriages with them [i.e., the nations that occupied the promised land]; thy daughter thou shalt not give unto his son, nor his daughter shalt thou take unto thy son (cf. Exod. 34:15–16). And this principle is also affirmed in the New Testament where the apostle Paul instructs believers to marry only in the Lord (I Cor. 7:39).

The purpose of this prohibition is stated in the next verse: For they will turn away thy son from following me, that they may serve other gods: so will the anger of the LORD be kindled against you, and destroy thee suddenly (v. 4). Unfortunately, this often happened. It happened, for example, when Balak sent out an army of Moabite prostitutes to disarm the Israelite men (Num. 25). Solomon also, in spite of his great wisdom, fell to it. I Kings 11 says that he loved many strange woman, i.e., foreign women of the nations with whom the Jews were not to intermarry. It goes on to say that he clave unto these in love. In other words, he had given himself heart and soul to his seven hundred wives and three hundred concubines. And when he gave them his heart, they turned his heart to go after their gods.

Remember that this was not an absolute prohibition against marrying people of other nations. The Lord’s concern was not that the Jews would marry outside the bloodline of Abraham, but that they would marry outside the faith of Abraham. There are examples in Scripture of very godly marriages between Jews and non-Jews. But they had to first adopt the faith of Abraham as their own. One example that particularly stands out here is Ruth, the Moabite wife of Mahlon, who after husband’s death chose to stay with her mother-in-law and to abide by her mother-in-law’s faith. She said, Whither thou goest, I will go; and where thou lodgest, I will lodge: thy people shall be my people, and thy God my God (Ruth 1:16). This alone reveals her faith and godliness. And not only so, but Boaz, a very godly and righteous man, fulfilled the part of the kinsman-redeemer after Ruth and Naomi returned to their own land. He married Ruth, and the Lord blessed their union with a son named Obed, an ancestor of David and also an ancestor of our Lord Jesus Christ. This relationship pleased the Lord and stands today as a wonderful example of a man and a woman who conducted themselves honorably in the courtship process.

Beloved, you must be just as concerned with your purity before God. The command not to become unequally yoked together with unbelievers applies to you, just as much as it does to anyone else.

Young people especially are tempted not keep this commandment. When you meet someone to whom you are attracted, you might to yourself, “I know so-and-so is not a Christian, but he’ll never become a Christian if I don’t date him.” But think about this for a minute. There are several problems with it. First of all, what you’re really saying is that it’s alright to break one of God’s commandments in order to keep another. The problem, of course, is that God’s laws never conflict with each other. Righteousness in one area is never a justification for sin in another. Second, this reasoning itself is untrue. There is nothing in the Bible that you have to date a person in order to evangelize him. It just doesn’t follow. Third, you don’t know for a fact that your dating-evangelism will be effective. The individual to whom you are attracted may never believe.  But meanwhile, you’ve given him your heart and soul, and you’ve placed yourself in a situation where it would be very easy to agree to an unequally yoked marriage.

The Word of God tells you not to go there. Don’t even consider it. Jesus prayed for your sanctification. Your holiness should be one of your chief concerns, too.

But sometimes the temptation is a little more subtle. Let’s say the person you meet is a member of a church. Perhaps he’s a Roman Catholic, a Methodist or a Presbyterian. But he’s not particularly interested in going to church, studying the Bible or praying. He has no real desire to walk with Christ. Keeping God’s commandments isn’t a high priority for him. Yet, he calls himself a Christian. Does the Word of God allow you to pursue an interest in such a person?

Here the answer is a little more problematic. Our text instructs us not be unequally yoked with unbelievers. But this guy professes to be a believer and is a member of a church. The Holy Spirit may have planted a seed of faith in him that hasn’t grown too much yet. Unfortunately, you cannot be sure either way. In this case, it’s probably wiser not to make any kind of commitment. If the Holy Spirit is working in him, it probably won’t be too long until you’ll be able to discern some fruit. And if you see no evidence of genuine faith over a reasonable period of time, then you should let this one go.

How can you really have fellowship with each other if you can’t fellowship in the things of the Lord? Is it really possible to have a marriage that glorifies Jesus Christ, if he is not present in every conversation? Can light fellowship with darkness, or righteousness with unrighteousness?

Having surveyed these few verses from Scripture, what have we learned? To begin with, we have seen that doing God’s will means that we keep his commandments. That’s the thrust of everything Paul wrote in our text.

But some Christians will still insist that we need to preview God’s plan for our lives. Look at Gideon, they say, didn’t he use a fleece to determine God’s blessing on his life? The answer is, no. Before Gideon put the fleece out, God had already told him that he would deliver the Israelites from Midianite oppression (cf. Judg. 6:14, 36). Gideon put the fleece out, then, not to discover God’s will, but to make sure that it was, in fact, God who had indeed spoken to him. Spurgeon says that God was very accommodating to Gideon’s weakness at this point. In any case, Gideon is not an example for us to follow.

God has spoken even more clearly to us — not in an audible voice as he probably did with Gideon, but through his inspired prophets and apostles. And in their sacred writings, we find that God’s will means that we avoid sexual immorality, fraud and anything else that displeases our Savior.

It’s true that that the Bible doesn’t state a preference for peppermint or spearmint. Nor does it say who should go to which college, or who should marry whom. But it does give the parameters upon which every decision must be made. We should ask ourselves, Which choice glorifies God and contributes to our sanctification? Which choice demonstrates our love for God’s law? Which choice shows that we walk with the Lord in covenant love?

As we walk in obedience to Biblical precepts, we’ll find happiness and contentment in the Lord’s will. Amen.

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