“So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. For the sinful nature desires what is contrary to the Spirit, and the Spirit what is contrary to the sinful nature. They are in conflict with each other, so that you do not do what you want.” (Galatians 5:16-17)
Our flesh tugs at us daily, entices us to do wrong, to sin, to allow the law of sin to work in us and condemn us. Daily we are subjected to ungodly principles, lifestyles, philosophies, and beliefs, none of which are of the Spirit, and all of which the flesh lusts for. Yet we were called to be set apart, to live not according to the desires of the flesh. The flesh sets itself against the Spirit, wars against it, resists it. But when we live according to the Spirit, we will not be under the condemnation that the law brings to our flesh man, for Christ has fulfilled that part of the covenant for us.
“The mind of sinful man is death, but the mind controlled by the Spirit is life and peace; the sinful mind is hostile to God. It does not submit to God’s law, nor can it do so.” (Romans 8:6-7)
The Spirit brings life, but the sin and faults of the flesh condemn us to death. That is why there was no way for us to bridge the gap on our own. That is why Christ stepped forward, came in the flesh, and yet, still overcame the flesh, so that the perfect Man could make all perfect in Him. Because He overcame the flesh, He condemned the sin that was there, giving Him the ability to fulfill the perfect law for all who walk in the Spirit as He walked in the Spirit, and not according to the flesh.