Letter 106: Augustine tells Macrobius not to rebaptize a catholic subdeacon.

I have heard that you are planning to rebaptize one of our subdeacons. Do not do it. As you wish to live to God, as you wish to please God, as you wish not to possess Christ's sacraments in vain, as you wish not to be separated forever from Christ's body, do not do it. I beg you, brother; for your own sake above all I beg you. At least give a little attention to what I say. Felicianus of Musti condemned Primian of Carthage, and in turn was himself condemned by Primian. Felicianus was for a long time in the sacrilegious schism of Maximian, and there he baptized many people through his churches. Now he is your bishop together with Primian, and no one is baptized after him. By what license, then, do you still think people should be rebaptized after us? Solve this question for me, and baptize me. But if you cannot solve it, spare another person's soul and spare your own. Or if you accuse me of speaking falsely about Felicianus, require me to prove it. If I do not prove it, then do what you think right. I will add this too: if I do not prove it, let me not be a bishop of my communion. But if I do prove it, do not be an enemy of your own salvation. My wish, brother and lord, is that you be at peace with us.

EPISTOLA 106 Scripta a. 409. A Macrobio, Donatianae partis apud Hipponem (uti ex Ep. 108 intellegitur) episcopo, agens ne subdiaconum quemdam rebaptizet DOMINO FRATRI DILECTO MACROBIO, AUGUSTINUS 1. Audivi quod quemdam subdiaconum nostrum rebaptizare disponis. Noli: sic Deo vivas, sic Deo placeas, sic Christi Sacramenta non inaniter habeas, sic non in aeternum a Christi corpore separeris. Noli, rogo te, frater, pro teipso te magis rogo; certe paululum attende quod dico. Felicianus Mustitanus Primianum Carthaginensem damnavit, et vicissim ab illo etiam ipse damnatus est. Diu Felicianus in sacrilego Maximiani schismate fuit, multos ibi per suas Ecclesias baptizavit, modo cum Primiano vester episcopus, sed et neminem post eum baptizans. Qua ergo licentia post nos adhuc rebaptizandum putatis? Hanc mihi solve quaestionem, et me baptiza: si hanc autem solvere non potes, parce alienae animae, parce tuae. Aut si me de Feliciano falsum dixisse arguis, exige ut probem; certe si non probavero, tunc fac quod putas. Addo etiam, si non probavero, non sim episcopus communionis meae; si autem probavero, noli esse inimicus salutis tuae. Opto te, domine frater, in pace esse nobiscum.