Luther says –

The Gospel is nothing but pure mercy. For he forgives you the debt, not because of your works and merit, but because he pities your cries, complaints and humiliation. This means that God has regard for an humble heart, as the Prophet David says in Psalm 51, 19: “The sacrifices of God are a broken spirit, a broken and a contrite heart, 0 God, thou wilt not despise.” Such a heart, he says, is broken and cast down and cannot help itself, and is glad when God gives it a helping hand; this is the best Sacrifice before God, and the true way to heaven.