14 Since, then, there is much difference between those who have sacrificed, what a want of mercy it is, and how bitter is the hardship, to associate those who have received certificates, with those who have sacrificed, when he by whom the certificate has been received may say, “I had previously read, and had been made aware by the discourse of the bishop, that we must not sacrifice to idols, that the servant of God ought not to worship images; and therefore, in order that I might not do this which was net lawful, when the opportunity of receiving a certificate was offered, which itself also I should not have received, unless the opportunity had been put before me, I either went or charged some other person going to the magistrate, to say that I am a Christian, that I am not allowed to sacrifice, that I cannot come to the devil's altars, and that I pay a price for this purpose, that I may not do what is not lawful for me to do.”
Now, however, even he who is stained with having received a certificate,— after he has learned from our admonitions that he ought not even to have done this, and that although his hand is pure, and no contact of deadly food has polluted his lips, yet his conscience is nevertheless polluted, weeps when he hears us, and laments, and is now admonished of the thing wherein he has sinned, and having been deceived, not so much by guilt as by error, bears witness that for another time he is instructed and prepared.
Source: The Epistles of Cyprian (New Advent)