6 But that they who are at Rome do not observe those things in all cases which are handed down from the beginning, and vainly pretend the authority of the apostles; any one may know also from the fact, that concerning the celebration of Easter, and concerning many other sacraments of divine matters, he may see that there are some diversities among them, and that all things are not observed among them alike, which are observed at Jerusalem, just as in very many other provinces also many things are varied because of the difference of the places and names. And yet on this account there is no departure at all from the peace and unity of the Catholic Church, such as Stephen has now dared to make; breaking the peace against you, which his predecessors have always kept with you in mutual love and honour, even herein defaming Peter and Paul the blessed apostles, as if the very men delivered this who in their epistles execrated heretics, and warned us to avoid them. Whence it appears that this tradition is of men which maintains heretics, and asserts that they have baptism, which belongs to the Church alone.
Source: The Epistles of Cyprian (New Advent)