A thought does not earn the right to be called truth simply because you have believed it for a long time.
A thought may feel true because of something you experienced. Someone may have spoken it over you. The world may have taught you to measure yourself by it. You may have repeated it so many times that you no longer question it.
But we don’t defeat a lie simply by replacing it with a more positive thought. We put the lie up against the Word of God.
The question is: “Does what I am believing agree with what God has said?” If it doesn’t, we do not have to keep agreeing with it. We take it captive and bring it into obedience to Christ.