Vocare (Latin for "to call")

Why does the Lord choose us?
What have we to offer infinite goodness?
When I think of His mercy and desire for me, I'm unable to speak. I just have to sit and write.
I can't express with words or unexpressible groanings what I feel. The closest would be overwhelming tears welling up inside from joy and sorrow.
But even that doesn't convey it. But I imagine that everyone knows this feeling even if we can't express it. The feeling of being overwhelmed by God (even if we don't know that's what it is).

I'm selfish, weak, poor and greedy.
What have I to offer infinite goodness?