True believers are not under the Law. The Law cannot condemn them although they feel sin and confess it. Great then is the power of the Spirit. Led by the Spirit, the Law cannot condemn the believer though he commits real sin. For Christ in whom we believe is our righteousness. He is without sin, and the Law cannot accuse Him. As long as we cling to Him we are led by the Spirit and are free from the Law. Even as he teaches good works, the Apostle does not lose sight of the doctrine of justification, but shows at every turn that it is impossible for us to be justified by works.
The words, “If you are led by the Spirit, you are not under the law,” are replete with comfort. It happens at times that anger, hatred, impatience, carnal desire, fear, sorrow, or some other lust of the flesh so overwhelms a man that he cannot shake them off, though he try ever so hard. What should he do? Should he despair? God forbid. Let him say to himself: “My flesh seems to be on a warpath against the Spirit again. Go to it, flesh, and rage all you want to. But you are not going to have your way. I follow the leading of the Spirit.”
When the flesh begins to cut up the only remedy is to take the sword of the Spirit, the word of salvation, and fight against the flesh. If you set the Word out of sight, you are helpless against the flesh. I know this to be a fact. I have been assailed by many violent passions, but as soon as I took hold of some Scripture passage, my temptations left me. Without the Word I could not have helped myself against the flesh.
Martin Luther, Commentary on Galatians 5:18
Lockdown, Luther, Law & Gospel | Galatians 5:18
Law, Grace, & Daily Living 