I'm responding here to something posted to the psychology community.
If we create and maintain our identities and self-images because of a need to provide our lives with a sense of unity and purpose... why do we have such a need in the first place?
Because God created us in His image, and He made us to have a purpose. He would give us our identities if we only got near Him to find them; but we spend our time trying to create them instead. I can't really post that to the psychology community--it would be considered off topic.