It’s about God’s grace
If we don’t have the grace of God, what do we have? I am completely reliant upon him and his grace. Nothing in me is good enough. I fall, I sin, I miss the mark, I can be rude, insensitive, and the list goes on.
We must guard against a false self-perception. The self-perception is that we are good enough. We become moralistic and think “I actually am good”. We are not good, only God is.