John Calvin Commentary Titus 2:15

"These things speak and exhort and reprove with all authority. Let no man despise thee." — Titus 2:15 (ASV)

Speak these things, and exhort, and reprove. This conclusion means the same as if he instructed Titus to dwell continually on that doctrine of edification, and never to grow weary, because it cannot be emphasized enough. He also instructs him to add the spurs of “exhortations and reproofs”; for people are not sufficiently admonished about their duty if they are not also strongly urged to perform it. He who understands those things which the Apostle has previously stated, and who speaks of them continually, will have grounds not only for teaching, but also for correcting.

With all authority. I do not agree with Erasmus, who translates ἐπιταγή as “diligence in commanding.” There is greater probability in the opinion of Chrysostom, who interprets it to mean severity against more atrocious sins; though I do not think that even he has grasped the Apostle’s meaning, which is that Titus should claim authority and respect for himself in teaching these things. For people given to curious inquiries, and eager about trivial matters, dislike the commandments to lead a pious and holy life, considering them too common and ordinary. So that Titus may counter this disdain, he is instructed to add the weight of his authority to his doctrine. It is for the same reason (in my opinion) that he immediately adds—

Let no man despise thee. Others think that Titus is instructed to gain people’s attention, and their respect for him, by the integrity of his life; and it is indeed true that holy and blameless conduct imparts authority to instruction. But Paul had another purpose in mind, for here he addresses the people rather than Titus. Because many had such sensitive ears that they despised the simplicity of the gospel, and because they had such a craving for novelty that hardly any room was left for edification, he forcefully counters the arrogance of such people and strictly commands them to stop despising, in any way, sound and useful doctrine. This confirms the remark I made at the beginning: that this Epistle was written to the inhabitants of Crete rather than to any single individual.