The Epistles of Cyprian

¹² Therefore, dearest brother, having explored and seen the truth; it is observed and held by us, that all who are converted from any heresy whatever to the Church must be baptized by the only and lawful baptism of the Church, with the exception of those who had previously been baptized in the Church, and so had passed over to the heretics. For it behooves these, when they return, having repented, to be received by the imposition of hands only, and to be restored by the shepherd to the sheep-fold whence they had strayed. I bid you, dearest brother, ever heartily farewell.