Galatians 5:16-18 (ESV)
But I say, walk by the Spirit, and you will not gratify the desires of the flesh.  For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do.  But if you are led by the Spirit, you are not under the law.
Day and night are opposites. Wet and dry are opposites. The desires of the Spirit and the desires of the flesh are opposites. The Spirit and the law are…opposites?
In v. 17, the Apostle Paul is clear. The desires of the Spirit and the desires of the flesh are complete opposites. The desires of the Spirit actually keep us from doing the desires of the flesh and vice versa. This makes sense. But the next comparison Paul makes is rather surprising. Verse 18 tells us that being “led by the Spirit” and being “under the law” are opposites.
Spirit and flesh are opposites. Spirit and law are opposites. So flesh and law…are the same?
At first glance, this seems absurd. How can breaking the speed limit and driving under the speed limit be the same exact thing? How can someone who completely abstains from alcohol be the same as an alcoholic?
When Paul refers to the law, he is still thinking about the battle between faith and circumcision. The law is not just a reference to God’s law in general but the desire of some to justify themselves before God with their good works. So Paul is saying that the person who indulges in their sinful desires and the person who keeps the law in order to earn God’s favor are the same. Both are driven by their self-centeredness.
The alcoholic is self-centered; he cares only for the pleasure of drunkenness even if it hurts everyone around him. Likewise, the self-righteous teetotaler is self-centered; she cares only for her own reputation and reward.
But Christians are no longer driven by the fleshly desires. No longer under the law, those led by the Spirit are free to serve and love others with no ulterior motive. No longer driven by selfish desire, we are free to be concerned solely with glorifying Christ.