From Eugene Peterson’s fantastic A Long Obedience in the Same Direction:
The basic conviction of a Christian is that God intends good for us and that He will get His way in us. He does not treat us according to our deserts, but according to His plan. He is not a police officer on patrol, watching over the universe, ready to club us if we get out of hand or put us in jail if we get obstreperous. He is a potter working with the clay of our lives, forming and reforming until, finally, he has shaped a redeemed life, a vessel fit for the kingdom.
“Mercy, [Yahweh], mercy!”: the prayer is not an attempt to get God to do what He is unwilling otherwise to do, but a reaching out to what we know that He does do, an expressed longing to receive what God is doing in and for us in Jesus Christ. In obedience we pray “Mercy!” instead of “Give us what we want.” We pray “Mercy!” and not “Reward us for our goodness so our neighbors will acknowledge our superiority.” We pray “Mercy!” and not “Punish us for our badness so we will feel better.” We pray “Mercy!” and not “Be nice to us because we have been such good people.”
We live under the mercy. God does not treat us as alien others, lining us up so that He can evaluate our competence or our usefulness or our worth. He rules, guides, commands, loves us as children whose destinies He carries in His heart.