For repentance must be taken in hand not only anxiously, but also quickly, lest perchance that father of the house in the Gospel who planted a fig-tree in his vineyard should come and seek fruit on it, and finding none, say to the vine-dresser: “Cut it down, why does it cumber the ground?” (Luke 13:7). And unless the vine-dresser should intercede and say: “Lord, let it alone this year also, until I dig about it and dung it, and if it bear fruit— well; but if not let it be cut down” (Luke 13:8-9 3).
Let us then dung this field which we possess, and imitate those hard-working farmers, who are not ashamed to satiate the land with rich dung and to scatter the grimy ashes over the field, that they may gather more abundant crops.
And the Apostle teaches us how to dung it, saying: “I count all things but dung, that I may gain Christ,” (Philippians 3:8) and he, through evil report and good report, attained to pleasing Christ. For he had read that Abraham, when confessing himself to be but dust and ashes, (Genesis 18:27) in his deep humility found favour with God. He had read how Job, sitting among the ashes, (Job 2:8) regained all that he had lost (Job 42:10). He had heard in the utterance of David, how God “raises the poor out of the dust, and lifts the needy out of the dunghill.”
Let us then not be ashamed to confess our sins unto the Lord. Shame indeed there is when each makes known his sins, but that shame, as it were, ploughs his land, removes the ever-recurring brambles, prunes the thorns, and gives life to the fruits which he believed were dead. Follow him who, by diligently ploughing his field, sought for eternal fruit: “Being reviled we bless, being persecuted we endure, being defamed we entreat, we are made as the offscouring of the world” (1 Corinthians 4:12-13).
If you plough after this fashion you will sow spiritual seed. Plough that you may get rid of sin and gain fruit. He ploughed so as to destroy in himself the last tendency to persecution. What more could Christ give to lead us on to the pursuit of perfection, than to convert and then give us for a teacher one who was a persecutor.
[St. Ambrose of Milan, Concerning Repentance, Book II)