5 What is that which looking forth we acknowledge? What is that which looking forth God acknowledges? What (because here He gives it) does He acknowledge? Hear what it is; that “All have gone aside, together useless they have become: there is not one that does good, there is not so much as one.” What then is that other question, but the same whereof a little before I have made mention? If, “There is not one that does good, is not so much as one,” no one remains to groan amid evil men.
Stay, says the Lord, do not hastily give judgment. I have given to men to do well; but of Me, He says, not of themselves: for of themselves evil they are: sons of men they are, when they do evil; when well, My sons. For this thing God does, out of sons of men He makes sons of God: because out of Son of God He has made Son of Man. See what this participation is: there has been promised to us a participation of Divinity: He lies that has promised, if He is not first made partaker of mortality.
For the Son of God has been made partaker of mortality, in order that mortal man may be made partaker of divinity. He that has promised that His good is to be shared with you, first with you has shared your evil: He that to you has promised divinity, shows in you love. Therefore take away that men are sons of God, there remains that they are sons of men: “There is none that does good, is not so much as one.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)