The Prescription Against Heretics by Tertullian
Chapter XVIII.--Great Evil Ensues to the Weak in Faith, from Any Discussion Out of the Scriptures Conviction Never Comes to the Heretic from Such a Process.
But with respect to the man for whose sake you enter on the discussion of the Scriptures, with the view of strengthening him when afflicted with doubts, (let me ask) will it be to the truth, or rather to heretical opinions that he will lean? Influenced by the very fact that he sees you have made no progress, whilst the other side is on an equal footing (with yourself) in denying and in defence, or at any rate on a like standing he will go away confirmed in his uncertainty by the discussion, not knowing which side to adjudge heretical. For, no doubt, they too are able to retort these things on us. It is indeed a necessary consequence that they should go so far as to say that adulterations of the Scriptures, and false expositions thereof, are rather introduced by ourselves, inasmuch as they, no less than we maintain that truth is on their side.