7 “Merciful and pitiful is the Lord; long-suffering, and very merciful”. “Sweet is the Lord to all, and His compassions reach into all His works”. Were He not such as this, there would be no seeking to recover us. Consider yourself: what did you deserve, O sinner? Despiser of God, what did you deserve? See if anything occur to you but penalty, if anything occur to you but punishment. You see then what was due to you, and what He has given, who gave gratis. There was given pardon to the sinner; there was given the spirit of justification; there was given charity and love, wherein you may do all good works; and beyond this, He will give you also life everlasting, and fellowship with the angels: all of His mercy....Hear the Scripture: “I will not the death of a sinner, but rather that he should turn, and live.” By these words of God, he is brought back to hope; but there is another snare to be feared, lest through this very hope he sin the more.
What then did you also say, thou who through hope sinnest yet more? “Whenever I turn, God will forgive me all; I will do whatsoever I will.” Say not then, “Tomorrow I will turn, tomorrow I will please God; and all today's and yesterday's deeds shall be forgiven me.” You say true: God has promised pardon to your conversion; He has not promised a tomorrow to your delay.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)