Among early Christian writers, the theme of repentance plays an enormous role, and whole treatises and sermons are devoted to it. Thus Tertullian (late second and early third century), for example, affirms (On Penitence 4.1): “God has promised his pardon [venia] through repentence [per paenitentiam], declaring to the people: ‘repent [paenitere] and I shall save you.’” So too Saint Ambrose (fourth century), in his treatise On Penitence: Against the Novatians (1.90–1), insists that a person who has committed sins in secret, if he repents sincerely, will be reintegrated into the congregation of the church: “I wish that the guilty person hope for pardon [venia], beg for it with tears, beg for it with groans, beg with the tears of all the people, entreat that he be pardoned [ignoscatur] … I have people who, during penitence, have made rivulets of tears in their faces, hollowed their cheeks with continual weeping, prostrated their bodies so that they might be trampled by all, and with their faces forever pale with fasting, presented the appearance of death in a breathing body.” This is the way to demonstrate sincere repentance and to earn forgiveness from God and the church.

Here again is Saint John Chrysostom, who preached nine homilies on the theme of repentance in Antioch in the years 386–7.