For Paul, Satan is a conquered, yet still dangerous, foe. Although “the God of peace will soon crush Satan under your feet” (Rom. 16:20), Satan is still “the god of this age,” who blinds the minds of unbelievers from seeing the light of the gospel of the glory of Christ (2 Cor. 4:4), and he is “the ruler of the kingdom of the air, the spirit who is now at work in those who are disobedient” (Eph. 2:2). There can be no fellowship between the realm of Belial and unbelievers, on the one hand, and the realm of Christ and believers, on the other; for they are as mutually exclusive as darkness and light (2 Cor. 6:14–16). Nevertheless, Satan tries to thwart believers at every point, either by leading them astray to “another gospel” (11:3–4) or by tempting them (1 Thess. 3:5; 1 Cor. 7:5). Likewise,…