D&C 93:37: Light and truth forsake that evil one.
This is one of those profound statements all crammed into 7 words. Light and truth, in other words the Glory of God, or Intelligence, forsakes that evil one.
How does glory, or light, or truth forsake that evil one? How does it do that? In what way is the evil one forsaken? Why does it forsake the evil one?
Satan's primary tool is the lie. When there is enough truth, there is no longer any reason to believe or teach a lie. Therefore, he has lost power. Consider this definition of forsake: To leave someone who needs or counts on you. The adversary is dependent on lies, and dependent on you believing the lies for him to have influence or control. Truth and light truly does forsake the evil one because you are freed from the grasp of his lies.
Gaining light and truth is also part of the proper definition of repentance. If I think I'm repenting and white knuckle some behavior, but gain no intelligence in so doing, have I repented? By repenting in the way the Lord asks we leave or depart from "that evil one" along with the previous mutual dependency. Light and truth is what we should be after.
It sets you free. Repentance forsakes that evil one. Repentance is not 5 steps. It's gaining knowledge and intelligence which informs our behavior which forsakes that evil one.