Our attitude to our fallen nature should be one of ruthless repudiation. For ‘those who belong to Christ Jesus have crucified the sinful nature with its passions and desires’ (Gal. 5:24). That is, we have taken this evil, slimy, slippery thing called ‘the flesh’ and nailed it to the cross. This was our initial repentance. Crucifixion is dramatic imagery for our uncompromising rejection of all known evil. Crucifixion does not lead to a quick or easy death; it is an execution of lingering pain. Yet it is decisive; there is no possibility of escaping from it.
Our attitude to the Holy Spirit, on the other hand, is to be one of unconditional surrender. Paul uses several expressions for this. We are to ‘live by the Spirit’ (Gal. 5:16, 18. 25). That is, we are to allow him his rightful sovereignty over us, and follow his righteous promptings.
Thus both our repudiation of the flesh and our surrender to the Spirit need to be repeated daily, however decisive our original repudiation and surrender may have been. In Jesus’ words, we are to ‘take up (our) cross daily’ and follow him (Lk 9:23). We are also to go on being filled with the Spirit (Eph. 5:18), as we open our personality to him daily. Both our repudiation and our surrender are also to be worked out in disciplined habits of life. It is those who ‘sow to the Spirit’ (Gal. 6:8) who reap the fruit of the Spirit. And to ‘sow to the Spirit’ means to cultivate the things of the Spirit, for example, by our wise use of the Lord’s Day, the discipline of our daily prayer and Bible reading, our regular worship and attendance at the Lord’s Supper, our Christian friendships and our involvement in Christian service. An inflexible principle of all God’s dealings, both in the material and in the moral realm, is that we reap what we sow. The rule is invariable. It cannot be changed, for ‘God cannot be mocked’ (Gal. 6:7). We must not therefore be surprised if we do not reap the fruit of the Spirit when all the time we are sowing to the flesh. Did we think we could cheat or fool God?
—Authentic Christianity (Nottingham, IVP, 1995)