What is the primary mission of the devil? To deceive. From the very beginning he came and told a lie to Eve, which Adam bought into. From the very beginning he came and told a lie to Eve, which Adam bought.That if they ate, they would be like God.
Rev. 20:3 says this speaking of the devil, "and he threw him into the abyss, and shut it and sealed it over him, so that he would not deceive the nations any longer"
John 8:44 says “You are of your father the devil, and you want to do the desires of your father. He was a murderer from the beginning, and does not stand in the truth because there is no truth in him. Whenever he speaks a lie, he speaks from his own nature, for he is a liar and the father of lies."
Thus the devil is a deceiver who has no truth in him, and seeks to keep us away from the truth. So what is it that sanctifies us?
John 17:17 Sanctify them in the truth; your word is truth.
God’s truth is what will set us free from lies and false realities that will hurt us.
Prov. 4:23 says "Watch over your heart with all diligence,
For from it flow the springs of life."
The heart basically directs us, but we can direct the heart. We are told to watch over our hearts. We are to hide the word of God deep within our heart.
Sanctification is thus fundamentally replacing the lies in our hearts with truth. A lie is unreal. For example, if we believe the lie that we can run through doors, then if we live according to such a lie, what would we do? We'd hurt ourselves by running into the door.
Truth however is ultimate reality. Those living in sin are those living according to a lie, against reality. If we know how to replace the lies in a person's heart, with truth, we have the key to sanctification.
What lies are in your heart? Beneath every struggle is a lie. Root out the lie, and believe deeply the truth. In no way at all is this easy, but we all have to go begin this process. Thus work the truth of God from your head to your heart.

