As we come to Ephesians 4: 17-24 Paul begins to teach the Ephesian church what must change in their lives. We need to put this into some context. Paul’s not arguing for salvation by works, in other words he’s not saying this is what you must do if you want to get to heaven. No, he spent the first three and a bit chapters reinforcing the idea that these Christians were saved because of what God had done for them. He chose them from before the creation of the world, planned for Jesus’ atoning sacrifice and opened their eyes so as they could respond to Jesus in faith. Paul’s now saying it’s because of what God has done, because they’ve been enabled to respond in faith, that there needs to be repentance as evidence that God has been at work, that repentance is the change in lifestyle which he’s about to detail.