12 My design in recounting these events has been to sketch for you the picture of your evil life and to set your misdeeds plainly before your eyes. I have wished to prevent you from making God's mercy and His abundant tenderness an excuse for committing new sins and to save you from crucifying to yourself the son of God afresh and putting Him to an open shame. For you may do these things if you do not read the words which follow the passage to which I have alluded. They are these: “The earth which drinks in the rain that comes oft upon it, and brings forth herbs meet for them by whom it is dressed, receives blessings from God: but that which bears thorns and briers is rejected and is near unto cursing; whose end is to be burned.”
Source: Letters (New Advent)