2 Corinthians 4
2 Corinthians 4:4: Who Is "the God of This Age"?
It is clear that Scripture (including the parts that Paul wrote) teaches that there is only one God (e.g., Rom 3:30; 1 Cor 8:6; Eph 4:6; 1 Tim 2:5; Jas 2:19). Who then is "the god of this age"? Why would Paul refer to another god if he believed that there is only one God?
As a Jew, Paul divided world history into two "ages": "this age" and "the age to come" (Eph 1:21). This age is a period when Satan has significant sway in the world, but in the age to come God's kingdom will be fully revealed and he will right all the wrongs from this age. When Paul submitted to Jesus as his Messiah, he gained a new perspective on this division of time. In Jesus the age to come has already arrived. Christians have already entered under the control of God and already experience the kingdom in the fruit of the Spirit (Rom 14:17) and the Spirit's power (1 Cor 4:20). This does not mean that the kingdom is fully present, for the full experience of the kingdom is in the future, when it will rule the earth (1 Cor 15:24). Thus Christians both experience the kingdom now and are yet to inherit the kingdom (Col 1:12).
Everyone, however, is not a Christian. This evil age is still very much present (Gal 1:4). In this age there is a "dominion of darkness" (Col 1:13) in which people are controlled by "the ruler of the kingdom of the air" (Eph 2:2). Paul refers to the human rulers of "this age" (1 Cor 2:8), the philosophers of "this age" (1 Cor 1:20) and the standards of "this age" (1 Cor 3:18). In this passage he refers to the being that controls "this age" as "the god of this age," rather than using one of his other titles, such as Satan (2 Cor 11:14). Paul refers to Satan by such a title, not because he is a god in the sense of being an ultimate being, but because he is the being who controls the lives of unbelievers (including blinding their minds) and the one whom they serve (even if they think that they are serving their own self-interest or money or some particular deity).
Therefore, for Paul there only is one true God. The true God is the ultimate God, the one ultimate being, for in the end Christ will put down all other dominions and authorities, including that of Satan, and "deliver the kingdom to the Father." Satan is not God; he is a being who will in the end bow the knee before God. Yet for now Satan holds sway over this age everywhere that people have not turned to Christ and thus been transferred from "the dominion of darkness" into "the kingdom of God's dear Son." Satan is not the ultimate God, but for those who have not turned to Christ, the dark lord is all the god that they know. That terrible reality is what Paul is recognizing in this verse.