John Chrysostom, on 2Cor 11:4

"For if he that cometh preacheth another Jesus whom we did not preach:" showing hereby that their deceivers were not Corinthians, but persons from some other quarter previously corrupted: wherefore he saith, "he that cometh." "If ye receive a different Spirit, if a different Gospel which ye did not accept, ye do well to bear" with him. What sayest thou? Thou that saidst to the Galatians, "If any preach another Gospel to you than that ye have received, let him be anathema;" dost thou now say, "ye do well to bear" with him? And yet on this account it were meet not to bear with, but to recoil, from them; but if they say the same things, it is meet to bear with them. How then dost thou say, "because they say the same things, it is not meet to bear with them?" for he says, "if they said other things, it were meet to bear with them." Let us then give good heed, for the danger is great, and the precipice deep, if men run past this carelessly; and what is here said giveth an entrance to all the heresies. What then is the sense of these words? Those persons so boasted as if the Apostles taught incompletely, and they were introducing somewhat more than they. For it is probable that with much idle talk, they were bringing in senseless rubbish so as to overlay these doctrines. And therefore he made mention of the serpent and of Eve who was thus deceived by the expectation of acquiring more. And alluding to this in the former Epistle also, he said, "Now ye are become rich, ye have reigned as kings without us;" and again, "we are fools for Christ's sake, but ye are wise in Christ."

Since then it was probable that using the wisdom which is without, they talked much idly, what he says is this: that "if these persons said any thing more, and preached a different Christ who ought to have been preached, but we omitted it, ye do well to bear with them." For on this account he added, "whom we did not preach." "But if the chief points of the faith are the same, what have ye the more of them? for whatsoever things they may say, they will say nothing more than what we have said." And observe with what precision he states the case. For he did not say, "if he that cometh saith any thing more;" for they did say something more, haranguing with more authority and with much beauty of language; wherefore he did not say this, but what? [If] "he that cometh preacheth another Jesus," a thing which had no need of that array of words: "or ye receive a different Spirit," (for neither was there need of words in this case;) that is to say, "makes you richer in grace;" or "a different Gospel which ye did not accept," (nor did this again stand in need of words,) "ye do well to bear" with him.