St. Dionysius the Great died ca. 265
…[I]ndeed, (Pope Stephen of Rome) had written letters about Helanus and Firmilianus, and about all who were established throughout Cilicia and Cappadocia, and all the neighboring provinces, giving them to understand that for that same reason he would depart from their communion, because they rebaptized heretics. And consider the seriousness of the matter. For, indeed, in the most considerable councils of the bishops, as I hear, it has been decreed that they who come from heresy should first be trained in Catholic doctrine, and then should be cleansed by baptism from the filth of the old and impure leaven.Asking and calling him to witness on all these matters, I sent letters. (Fragments: Epistle 6)
