The Prescription Against Heretics by Tertullian
Chapter XXIII.--The Apostles Not Ignorant The Heretical Pretence of St. Peter's Imperfection Because He Was Rebuked by St. Paul. St. Peter Not Rebuked for Error in Teaching.
Now, with the view of branding the apostles with some mark of ignorance, they put forth the case of Peter and them that were with him having been rebuked by Paul. |Something therefore,| they say, |was wanting in them.| (This they allege,) in order that they may from this construct that other position of theirs, that a fuller knowledge may possibly have afterwards come over (the apostles,) such as fell to the share of Paul when he rebuked those who preceded him. I may here say to those who reject The Acts of the Apostles: |It is first necessary that you show us who this Paul was, -- both what he was before he was an apostle, and how he became an apostle,| -- so very great is the use which they make of him in respect of other questions also. It is true that he tells us himself that he was a persecutor before he became an apostle, still this is not enough for any man who examines before he believes, since even the Lord Himself did not bear witness of Himself. But let them believe without the Scriptures, if their object is to believe contrary to the Scriptures. Still they should show, from the circumstance which they allege of Peter's being rebuked by Paul, that Paul added yet another form of the gospel besides that which Peter and the rest had previously set forth. But the fact is, having been converted from a persecutor to a preacher, he is introduced as one of the brethren to brethren, by brethren -- to them, indeed, by men who had put on faith from the apostles' hands. Afterwards, as he himself narrates, he |went up to Jerusalem for the purpose of seeing Peter,| because of his office, no doubt, and by right of a common belief and preaching. Now they certainly would not have been surprised at his having become a preacher instead of a persecutor, if his preaching were of something contrary; nor, moreover, would they have |glorified the Lord,| because Paul had presented himself as an adversary to Him. They accordingly even gave him |the right hand of fellowship,| as a sign of their agreement with him, and arranged amongst themselves a distribution of office, not a diversity of gospel, so that they should severally preach not a different gospel, but (the same), to different persons, Peter to the circumcision, Paul to the Gentiles. Forasmuch, then, as Peter was rebuked because, after he had lived with the Gentiles, he proceeded to separate himself from their company out of respect for persons, the fault surely was one of conversation, not of preaching. For it does not appear from this, that any other God than the Creator, or any other Christ than (the son) of Mary, or any other hope than the resurrection, was (by him) announced.