Prescription against Heretics 4

Rather let us remember both the sayings of the Lord and the letters of the apostles, which both foretold to us that heresies would come and laid down in advance that they must be shunned; and as we are not terrified that they exist, so let us not be astonished that they have the power on account of which they must be shunned. The Lord teaches that many ravening wolves will come in sheep's clothing. What are these sheep's clothes but the outward surface of the Christian name? Who are the ravening wolves but deceitful thoughts and spirits lurking within to harass the flock of Christ? Who are the false prophets but false preachers? Who the false apostles but adulterous evangelists? Who are the antichrists, both now and always, but the rebels against Christ? Such will heresies be, assailing the church by the perversity of their doctrines no less than the Antichrist will then persecute it by the savagery of persecution; except that persecution makes even martyrs, heresy only apostates. And so “there had to be heresies too, so that those who are approved might be made manifest,” both those who stood firm in persecutions and those who did not swerve into heresies. For it does not help to regard as approved those who change their faith into heresy, though they interpret it the other way for themselves, because he said elsewhere, “Test all things; hold fast what is good.” As if it were not possible, when everything is tested badly, to stumble by error into choosing something bad.