Prepare for Battle
As you begin to reclaim your mind and thought life from the enemy, know that he won't easily give up the place that he's had. You will have to do battle against his lies and confusion. You must declare out loud that you will not allow any outside force to do your thinking—man or spirit. There are spiritual laws that demons must obey. They can't stay when you've commanded them to leave. Your power and authority come from the name of Jesus, the blood of Jesus, and the Word of God. Ask God to give you discernment about the lies of the devil.
Think About What You're Thinking About
As you recognize a thought that is a lie, always defend yourself out loud. This means speaking to Satan and the evil forces out loud, binding them in the name of Jesus, and forbidding them to lie to you and use your mind as their playground. As you continue to use this prescription regularly, you'll regain your peace, your memory, restful nights, and the ability to concentrate and comprehend.
Stand Firm—You're Not Alone
You are in a battle that all of God's children fight (see Ephesians 6:12). Make up your mind not to give up! According to Colossians 3:2, set your mind on things above and keep it set! As you begin this battle, things may seem to get worse before they get better. This is because the demonic powers are fighting to keep their place. Call upon God's grace in the name of Jesus, and He will give you the power of the Holy Spirit to completely overcome every evil tendency.
Don't Give Up!
Remember, regaining your mind is a process. We all fail at one time or another. God knows our weaknesses; that's why He gave us 1 John 1:9. Just ask for forgiveness and envision the blood of Jesus washing away your sin. Continue claiming that your mind belongs to you, and with Jesus' help you will be victorious.
When you hear a lie going through your mind, say out loud:
"Satan, you are a liar. I will not receive (or believe) your lie in the name of Jesus" (see 2 Corinthians 10:5). "I remind you that it is written, …He who lives in [me] is greater (mightier)than he who is in the world. I command you to bow your knee to the name of Jesus and leave me." (see 1 John 4:4).
You have now pulled the lie out—just as you pull a weed out of the ground. But an empty hole remains where the weed once was. You must fill that space with Scripture. Begin to meditate on God's Word or sing a praise song to God. Whatever it is you choose to do, make a conscious effort to fill your mind with good, pure, wholesome and lovely thoughts (see Philippians 4:8).