1 Corinthians 10:3-5; "We are human, but we don’t wage war as humans do. We use God’s mighty weapons, not worldly weapons, to knock down the strongholds of human reasoning and to destroy false arguments. We destroy every proud obstacle that keeps people from knowing God. We capture their rebellious thoughts and teach them to obey Christ."(NLT)
The scripture above throws light on the activity of the mind. The bible says that as a man thinketh in his heart so is he (Proverbs 23:7a), the heart it's talking about is your mind, not the physical heart because the physical heart only pumps blood to different organs of your body.
In fact, what the nervous system is to the body, the soul is to the spirit and what the brain is to the nervous system, the mind is to the soul. Therefore our mind is responsible for the outcome of our lives since the spiritual controls the physical.
Now there are thoughts called "strongholds", these thoughts fight against the things of God in our mind through unbelief. These strongholds develop with time when we give our mind to things that are against or contrary to the word of God. Cast it down!
Do not let wrong thoughts rule your mind, thoughts that are contrary to the word of God, it will only ruin your life. The devil will only succeed in winning you over if your mind is captured in rebellious thoughts. Think the right way and God will shower his glory upon you.
Romans 12:2 says; "Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is, his good, pleasing and perfect will."(NIV)
Heavenly Father I thank you for your word, I cast down every stronghold operating in my mind against the knowledge of Christ, I refuse to let the devil take hold of my reasoning, I have the mind of Christ. I have victory over every attack in my mind, in Jesus name! Amen!