John Calvin: "Paul now forbids him to waste much time in debating with heretics, because battle would lead to battle and dispute to dispute. Such is the cunning of Satan, that, by the impudent talkativeness of such men, he entangles good and faithful pastors, so as to draw them away from diligence in teaching. We must therefore beware lest we become engaged in quarrelsome disputes; for we shall never have leisure to devote our labors to the Lord’s flock, and contentious men will never cease to annoy us.
When he commands him to avoid such persons, it is as if he said that he must not toil hard to satisfy them, and even that there is nothing better than to cut off the handle for fighting which they are eager to find. This is a highly necessary admonition; for even they who would willingly take no part in strifes of words are sometimes drawn by shame into controversy, because they think that it would be shameful cowardice to quit the field.
Besides, there is no temper, however mild, that is not liable to be provoked by the fierce taunts of enemies, because they look upon it as intolerable that those men should attack the truth, (as they are accustomed to do,) and that none should reply. Nor are there wanting men who are either of a combative disposition, or excessively hot-tempered, who are eager for battle. On the contrary, Paul does not wish that the servant of Christ should be much and long employed in debating with heretics."