Paul’s words, “I am completing what remains of Christ’s sufferings,” did not mean that Christ’s suffering was inadequate to save people. Paul believed that Christ’s suffering on the cross alone paid for believers’ salvation from sin (Romans 3:23–25). (See also 1 Corinthians 1:18–31; 2 Corinthians 5:16–21; Galatians 1:4; Colossians 2:13–14.)
While we know what Paul did not mean by these words, we must consider several interpretations regarding what he did mean. There are three main views:
1. One view comes from the Jewish belief that an anointed ruler would come and God’s people would be called upon to suffer (Daniel 12:1). However, God would set a limit to these sufferings. Paul saw himself as suffering on behalf of the church, thereby completing what remained of that set amount of suffering. Some commentators consider that Paul thought that by his suffering he actually was saving others from suffering. This view seems unlikely, however, because Paul was tying suffering to the spread of the gospel, not to preparation for the end times.
2. Referring to Paul’s words in Philippians 3:10 where Paul wanted to suffer with Christ, he may have meant that he wanted to complete in himself what was lacking in his understanding of Christ’s suffering. This also seems unlikely in this context, however, because Paul was emphasizing the believers’ completeness in Christ.
3. Another view refers to the mystical union between Paul and Christ and between Christ and the church. What Paul suffered, Christ suffered, because Paul was a member of Christ’s body on earth. What Christ began as suffering with his persecution and rejection on earth, all believers complete in his continuing body on earth. This view seems most likely because it stresses that the cause of the suffering would be the extension of the gospel to all the world. Paul shared the suffering of the Messiah as he brought the Messiah’s message to the world.
Jesus had warned his followers to expect affliction (John 15:20–21). This suffering would not be limited to Paul. By identifying themselves with Christ, all believers would face affliction. Not all would face imprisonment, as Paul did, but all would have varying degrees and kinds of suffering simply because they have allied themselves with Christ in a world hostile to Christ. But this suffering should be cause for rejoicing. Suffering does not mean that Christ is losing ground, but that he is gaining it and that the present age is passing away to eventually herald in the age to come when Christ will reign.
24 Now I rejoice in my sufferings for your sake, and fill up on my part that which is lacking of the afflictions of Christ in my flesh for his body’s sake, which is the church; 25 whereof I was made a minister, according to the dispensation of God which was given me to you-ward, to fulfil the word of God, 26 even the mystery which hath been hid for ages and generations: but now hath it been manifested to his saints, 27 to whom God was pleased to make known what is the riches of the glory of this mystery among the Gentiles, which is Christ in you, the hope of glory: 28 whom we proclaim, admonishing every man and teaching every man in all wisdom, that we may present every man perfect in Christ; 29 whereunto I labor also, striving according to his working, which worketh in me mightily.