‘But I say, “Walk by the Spirit and you will not fulfil the longing of the flesh. For the flesh longs against the Spirit, and the Spirit longs against the flesh. For these are contrary, the one to the other, that you may not do the things that you would.'
But how different that is from being a Christian. For a Christian walks by the Spirit, and in accordance with His will. They have previously learned that Christ lives in them in His resurrection life (Galatians 2:20), that they have received the Spirit (Galatians 3:2), that they have been adopted as sons of God, receiving the Spirit of His Son into their hearts (Galatians 4:5-6), that Christ is to be formed within them (Galatians 4:19), that they wait for the hope of righteousness through the Spirit (Galatians 5:5). Now Paul tells them that they must walk by the same Spirit.
He agrees that a battle constantly takes place in each Christian's life, for we live in human bodies. We have fleshly desires. Our ‘flesh' longs for things we should not long for, for position, fame, money, drink, sexual satisfaction however achieved, prominence and so on (or at least the desire for one or the other is always there deep down ready to break through). But, if we are Christians we also have within us the Spirit longing for righteousness. And these are at constant warfare, or seeking to be so. Both pull us in different ways. And Paul tells us that we must listen to the Spirit and ‘walk by the Spirit'. This means walking as He wants us to by His power, in full responsiveness to His promptings through God's word and prayer. We must see Christ as living within us and let Him live through us.
On His side He has promised that He will enable us to overcome every temptation that besets us (1 Corinthians 10:13), and that He will work within us to will and do of His good pleasure (Philippians 2:13). And the fact is that we desperately need Him and the power of His risen life, for in every Christian's life a great battle is taking place, and never more so than when it is not noticed. Thus we must ‘work out' what God works in us, with greatest care (Philippians 2:12).
The reality is that the Spirit and the flesh are at constant loggerheads. ‘For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh'. The flesh constantly tugs at us like a tug-of-war team, seeking to drag us away from what the Spirit desires, for the flesh is earthly and thinks of what is earthly. In some the pull of the flesh may be weaker as a result of long experience of God but the flesh is ever willing to wait for the weak moment, so that it can strike, as the Serpent did in the Garden of Eden. On the other hand the Spirit seeks to draw us the other way towards the heavenly. ‘For these are against each other, to prevent you from doing what you would'. In other words, as Christians ‘what we would' is to follow the Spirit, but the flesh regularly seeks to prevent us from doing so (compare Romans 7:14-25).
But Paul is not here saying that human flesh is, in itself, intrinsically evil. He is rather saying that that flesh contains desires and longings which have to be controlled. In the Christian the Spirit will constantly act as a powerful pull away from following fleshly longings. But the flesh will just as constantly and fiercely pull back. The Christian certainly wants to be pure, and loving, and good and righteous, (otherwise his profession must be in doubt), but there will always be something that is seeking to drag him down, ‘the pull of the flesh'. Thus he does not always behave in the way that in his best moments he wants to.
In some it will be greed for power or fame or status, in others it will be envy of those who have achieved such, in others the problem of a strong sex drive, or a drink problem, in others a sense of self-righteousness, a desire to be recognised as ‘good'. But it will be there in all, and never more dangerous than when not recognised. But the Spirit can enable us to overcome, not by our struggling to keep a set of detailed rules, (a sure way to fail), but by constantly looking to Him in prayer and through His word, and responding to His prompting. As it has been well put, ‘His word will keep me from sin, and sin will seek to keep me from His word'.
However, a word of warning from Paul. Very often there is only one way to fight the desires that arise within us, and paradoxically that way is to flee (2 Timothy 2:22), to engage in a strategic withdrawal. Being led by the Spirit involves being where the Spirit wants us to be, it also involves not being where the Spirit does not want us to be. If you carry the means of temptation with you, or go where such temptation will beset you, you cannot expect the Spirit to intervene. You have already said ‘no' to Him.
‘That you may not do the things that you would.' This refers to the power of the flesh to drag us down from what the Spirit is doing within us, for what the Christian ‘would' is to fulfil all righteousness. Indeed if that is not his wish his position in Christ must be in doubt. The point is that the pull of the flesh is our enemy to be faced up to (often by fleeing) and to be overcome, for we are no longer after the flesh but born of the Spirit (Galatians 4:29).
Are our eyes fixed on some object of pleasure that is enticing us to sin. Then what we must do is run. ‘Flee from youthful desires'. That is being led by the Spirit. Is Satan putting evil thoughts into our minds, and setting our thoughts on them? Then it will be no good running. Our thoughts will go with us. What we must do then is make use of the armour of God and the shield of the word of God. Is he suggesting false ways to us? Then we must ‘resist the Devil and he will flee from you'. The Spirit will always lead us in accordance with the word of God.