I constantly struggle with the desire to prove myself to people. I want to achieve something that proves my worth, my wisdom, my character, my giftedness, or whatever. What this is changes through life - in education, I feel I need to get the best in my year to prove I'm clever. And so on.
I am a son of the living God. What could I possibly achieve that would give me something greater than that with which to prove myself? What could there possibly be that shows my worth more than that? Absolutely nothing - I might as well stop trying.
And so I boast not in myself, but in the one who by his grace made this reality so. I boast in God, I boast in Jesus, through whom I am adopted into the family of God.