3 “Confession and glorious deeds are His work”. What is a more glorious deed than to justify the ungodly? But perhaps the work of man prevents that glorious work of God, so that when he has confessed his sins, he deserves to be justified....This is the glorious work of the Lord: for he loves most, to whom most is forgiven. This is the glorious work of the Lord: for “where sin abounded, there did grace much more abound.” But perhaps a man would deserve justification from works. “Not,” says he, “of works, lest any man boast. For we are His workmanship, created in Christ Jesus unto good works.” For a man works not righteousness save he be justified: but by “believing on Him that justifies the ungodly,” he begins with faith; that good may not by preceding show what he has deserved, but by following what he has received....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)