Cyprian

When some infirmity and weakness and desolation attacks us, then our power is made perfect, and our faith is crowned if it has stood firm through temptation.

And yet to these persons themselves repentance is granted, and the hope of lamenting and atoning is left, according to the saying of the same apostle: "I fear lest, when I come to you, I shall bewail many of those who have sinned already, and have not repented of the uncleanness, and fornication, and lasciviousness which they have committed.".
Also in the same: "But I fear lest perchance, when I come to you, God may again humble me among you, and I shall bewail many of those who have sinned before, and have not repented, for that they have committed fornication and lasciviousness."

That all sins may be forgiven him who has turned to God with his whole heart... Also in the same [second Epistle of the blessed Paul to the Corinthians]: "I told you before, and foretell you as I sit present; and absent now from those who before have sinned, and to all others; as, ill shall come again, I will not spare."