The un-surrendered self is an unnatural self. The self was made for wholehearted worship of the One true God. The self is sick and needs healing. It is broken and needs to be made whole. Healing begins by acknowledging God above the self and surrendering fully to Him. Then the self ceases to be the center and God becomes the center. He can re-shape the self to something whole and healthy.
“You were taught, with regard to your former way of life, to put off your old self, which is being corrupted by its deceitful desires; to be made new in the attitude of your minds; and to put on the new self, created to be like God in true righteousness and holiness.” Ephesians 4:22-24 (NIV)