Since some around GT like Cyprian's words, as if they're sacrosanct, here's the introduction to something else he and 86 bishops said against Pope Stephen of Rome who allowed that heretical baptism was equivalent to Christian baptism.
The Seventh Council of Carthage under Cyprian.46734673 [On councils, see Oxford trans., pp. 232, 240.]
Concerning the Baptism of Heretics. The Judgment of Eighty-Seven Bishops on the Baptism of Heretics.
Promium.When http://www.ccel.org/ccel/schaff/anf05.iv.vi.i.html?highlight=rome,stephen#highlightStephen, Bishop of Rome, Had by His Letters Condemned the Decrees of the African Council on the Baptism of Heretics, Cyprian Lost No Time in Holding Another Council at Carthage with a Greater Number of Bishops. Having Therefore Summoned Eighty-Seven Bishops from Africa, Numidia, and Mauritania, Who Assembled at Carthage in the Kalends of September, a.d. 258, This Third Council on the Same Matter of Baptism Was Then Celebrated; At the Beginning of Which, After the Letters on Either Side Had Been Read, Cyprian, by Implication, Condemns the Assumption of Stephen.4674
... Cyprian of Carthage said: The letter which was written to our colleague Jubaianus very fully expresses my opinion, that, according to evangelical and apostolic testimony, heretics, who are called adversaries of Christ and Antichrists, when they come to the Church, must be baptized with the one baptism of the Church, that they may be made of adversaries, friends, and of Antichrists, Christians
ANF05. Fathers of the Third Century: Hippolytus, Cyprian, Caius, Novatian, Appendix - Christian Classics Ethereal Library
Pope Stephen of Rome, to the contrary, permitted the adversaries and antichrists' baptisms to be the same as those in the Church. Cyprian, etal, disagreed.
The Seventh Council of Carthage under Cyprian.46734673 [On councils, see Oxford trans., pp. 232, 240.]
Concerning the Baptism of Heretics. The Judgment of Eighty-Seven Bishops on the Baptism of Heretics.
Promium.When http://www.ccel.org/ccel/schaff/anf05.iv.vi.i.html?highlight=rome,stephen#highlightStephen, Bishop of Rome, Had by His Letters Condemned the Decrees of the African Council on the Baptism of Heretics, Cyprian Lost No Time in Holding Another Council at Carthage with a Greater Number of Bishops. Having Therefore Summoned Eighty-Seven Bishops from Africa, Numidia, and Mauritania, Who Assembled at Carthage in the Kalends of September, a.d. 258, This Third Council on the Same Matter of Baptism Was Then Celebrated; At the Beginning of Which, After the Letters on Either Side Had Been Read, Cyprian, by Implication, Condemns the Assumption of Stephen.4674
... Cyprian of Carthage said: The letter which was written to our colleague Jubaianus very fully expresses my opinion, that, according to evangelical and apostolic testimony, heretics, who are called adversaries of Christ and Antichrists, when they come to the Church, must be baptized with the one baptism of the Church, that they may be made of adversaries, friends, and of Antichrists, Christians
ANF05. Fathers of the Third Century: Hippolytus, Cyprian, Caius, Novatian, Appendix - Christian Classics Ethereal Library
Pope Stephen of Rome, to the contrary, permitted the adversaries and antichrists' baptisms to be the same as those in the Church. Cyprian, etal, disagreed.