I've done a little bit of thinking about this recently in light of preaching at a conference in a few weeks. I've been thinking about how our identity in Christ is portrayed in the Bible and how we often experience it.
Let me get to the 'splainin (as Desi used to Lucy).
Here's the way I've heard the Identity issue taught: we are who God has made us to be. Satan will come along and say differently. He's a liar and we shouldn't listen. We are the righteousness of God in Christ. We are a new creation. We are completely forgiven. We are under zero condemnation. We are conquerors and victors. We are sons of God. And on and on we could go.
Completely biblical. Every word. And that's exactly right. Every word.
If there's a weakness in this line of thinking and teaching, here is where it is (in my humble opinion). I think it leads us to think about us too much and about God too little. We apply this teaching like salve to hurt feelings, souls, or thoughts. It's dangerously close to becoming a biblical version of positive self-talk (which is good) without God in the picture (which is not good).
Here is the way I think would be more helpful:
We are sons of God and He is our Father
We are a new creation and He is our Creator
We are completely forgiven and He is our Forgiver
We are under no condemnation and He is our Judge
See what happened there? We're not thinking about ourselves except in relation to God. For what it's worth, I think that brings Identity out of the realm of mere self-talk and roots it in relationship. David spoke to himself in Psalms 42-43 - "Why are you downcast, O my soul?" - but didn't stop there. "Hope in God, for I will yet praise Him." Did you see the relationship in that last phrase? I think that's the most biblical way to think about it.
But that's just me thinking thoughts...