Paul reminds his Roman readers that they are to live like children of the day in the night that marks this world. And he uses a simple illustration to explain further what he wants them to do. The illustration he uses is changing clothes. The old clothes we are to through off are the works of darkness and the new clothes we are to put on is the armour of light.
The apostle lists some works of darkness in verse 13 and it is a horrible list: ‘not in orgies and drunkenness, not in sexual immorality and sensuality, not in quarrelling and jealousy.’ He says that these practices are unsuitable for the daytime, and indeed if people do them in daytime in public they will get arrested for doing so. Instead, as far as Christians are concerned, those practices belong to the life that has gone. They should be treated as clothes that are unsuitable to wear.
Instead the Christians are to put on the armour of light. The word ‘armour’ indicates that the Christian’s God-given attire is protective against the influences of darkness. How does it do so? We have to recognise that we cannot be neutral in our commitment, so we will be wearing clothes that identify with the darkness or we will be wearing armour that connects us to the light. So we are responsible to put on the correct clothes. This is another way of saying that Christians work out in their lives what God has worked into their souls.
In the conflicts that soldiers faced, their armour covered the various parts of their bodies. Believers are involved in a spiritual conflict, and the battles are connected to their minds, affections and wills. The enemies are the world, the flesh and the devil. How do we protect our minds when we are tempted by one or more of those enemies? How do we protect our affections when we are tempted by one or more of those enemies? How do we protect our wills when we are tempted by one or more of those enemies?
Paul provides the answer to those questions in verse 14 where he writes: ‘put on the Lord Jesus Christ, and make no provision for the flesh, to gratify its desires.’ The answer is twofold – positively we are to put on Jesus (Paul is still using the imagery of clothing) and negatively we are not to feed our sinful tendencies. So we can imagine a situation where a Christian is tempted to think about one of the sins that Paul mentions in verse 13. What does he do to deal with that attack? Obviously he can pray for the attack to stop. But what if the attack does not stop? The answer is to think about Jesus. Even when he prayed, he should have asked God to enable him to think about Jesus.
That sounds elementary. Indeed, it should be automatic for a Christian to do so. Nevertheless, we don’t find it easy. Does this mean that God makes it hard for us to defeat our spiritual opponents? The answer is no. Yet he does require us to use means and if we want to think about Jesus in the moment of attack we will need to spend time reading about Jesus before the attack happens.
I would say that we should something about Jesus every day from the Bible. It is possible to read the Bible in a manner that prevents us reading about Jesus. Reading about Jesus is the equivalent of a soldier polishing his armour, so when a Christian needs to use his armour he can think about what he read about Jesus.