How should Christians relate to the world around us? Should we withdraw, or should we engage? How do we know which action to do when? It’s not question with a simple answer, is it? On the one hand, there are plenty of reasons why we might think we should withdraw from the world. Paul tells believers in his letter to the Ephesians: “you were dead because of your offenses and sins, in which you once walked, according to the age of this world” (Ephesians 2:1–2), and so “we were, by nature, children of wrath”, deserving of God’s righteous judgment (2:3). But Christians are people who have been rescued from the evils of the world. God has “raised us together with Christ, and seated us together with him in the heavenly places in Christ Jesus” (2:6–7). So we should “no longer walk as the gentiles walk: in the futility of their minds” (4:17). Instead, we should “take off the old humanity, according to the former way of life, which is being corrupted according to deceitful desires” (4:22), and instead “put on the new humanity, which has been created according to God in the righteousness and devotion that come from the truth” (4:24). Our behaviour must be completely different from the world’s—no sexual immorality, impurity, or greed. “It’s because of these things that the wrath of God is coming on the children of disobedience. So don’t become partners with them” (5:6–7). All of these things that Paul says in Ephesians seem to give us plenty of reasons to withdraw from the world and have nothing to do with it. But on the other hand, there are also plenty of reasons for us to engage with the world. Christians are people who are caught up in God’s great plan “to sum up all things in Christ: things in heaven and things on earth, in him” (1:10). God is achieving this plan through the preaching of the gospel, the “word of truth”, which brings salvation to people. Christians are people who have come to believe and trust in Christ the missionary, the one who “came and preached the gospel: peace to you who were far away, and peace to those who were close” (2:17). Paul the apostle is caught up in this mission; he is a “minister of the gospel” whose task is “to preach to the gentiles the gospel” (3:7–8). And God’s people, too, are caught up in this “work of ministry” and mission; we should be “speaking the truth in love” and so seeing the body of Christ grow (4:14–15). So gospel ministry and mission is central to our identity as Christians. And all of these things give us plenty of reasons to engage with the world—so that people might hear the gospel, come to Christ, and be saved. So what should we do? Should we withdraw,