God will only work with what you give Him. We are called to submit everything to Him, but God gives us free will. The Lord doesn’t make us do anything. In your life He cannot truly be Lord at all until He is Lord of all. To experience the renewed mind and newness of life we must give our whole selves to Him.
It is very easy to surrender most of ourselves to Christ, but hold on to a few ‘little’ things. God doesn’t want most of you, though, He wants it all! As long as you try to hold on to whatever it is you will a sense of disconnect between you and Jesus. He knows what it is and so do you. Nothing is more valuable than knowing Jesus more. Jesus gave His all for you and He just wants the same back.