Sanctification is the process of eliminating the hindrances that stop us from becoming like Christ and living in His fullness.
Sanctification always deals with the heart, the inner-man and from there the term inner-healing is coined.
Sanctification deals with the inner-man, our character and not our personality.
Our personality is what we show those around us that are not in our inner circle of close relationships, our character on the other hand is our true self that others see when they get close to us, what we sometimes try to hide, especially in religious churches, for we can feel judged, measured and condemned.
Jesus always looks to the heart first, He knows if the heart is surrendered to change into His likeness the rest will follow. Religious people look at the outside personality first, and want to change it or make it look good if not better. See Matthew Ch23Verse26.
The process in becoming like Christ Jesus is allowing Him to deal with our character, those hidden parts of ourselves.
This is why we are called to walk the narrow path, because it is not an easy one as compared to walking the broad path as the world does.