According to 2 Corinthians 10:3-5, the mind is the battlefield. We are in a war, but it is a spiritual war that must be fought spiritually with spiritual weapons.
Using our spiritual weapons, we refute the enemy’s lies, arguments, theories, reasonings, and every other thing that tries to exalt itself against the truth of God’s Word.
We must take our thoughts captive and not indulge in the fleshly luxury of receiving and meditating on every thought that falls into our heads. We must exercise ourselves to "think about what we are thinking about." This takes some discipline and practice.
The primary weapon with which we do battle is the Word of God used in various ways preached, taught, sung, confessed, meditated upon, written, and read. The Word of God has a cleansing effect on our minds and lives any way we use it.
I once had a negative, wandering, wondering mind. Now, after years of applying the Word of God and a lot of help from the Holy Spirit, I can say with confidence, "I have the mind of Christ." (1 Corinthians 2:16.)
You can win the battle in your mind every stronghold can be torn down and every deception uncovered. Don’t settle for anything less than complete freedom!
"Thank You, Lord, for Your Word that renews my mind and sets me free. I have the mind of Christ! In Jesus’ name, amen."