John Calvin Commentary Titus 3:9

"but shun foolish questionings, and genealogies, and strifes, and fightings about law; for they are unprofitable and vain." — Titus 3:9 (ASV)

But avoid foolish questions. There is no need to debate at length about the interpretation of this passage. He contrasts “questions” with sound and certain doctrine. Although it is necessary to seek in order to find, there is still a limit to seeking, so that you may understand what is useful to know, and then, that you may adhere firmly to the truth once it has been known. Those who inquire curiously into everything, and are never at rest, may truly be called Questionarians. In short, what the schools of the Sorbonne consider worthy of the highest praise—is condemned here by Paul; for the entire theology of the Papists is nothing other than a labyrinth of questions. He calls them foolish; not that they appear to be so at first sight (for, on the contrary, they often deceive by a vain display of wisdom), but because they contribute nothing to godliness.

When he adds genealogies, he mentions one class of “foolish questions”; for instance, when curious men, forgetting to gather fruit from the sacred histories, focus on the lineage of races and trivial matters of that nature, with which they weary themselves to no advantage. We spoke of that folly towards the beginning of the First Epistle to Timothy.

He properly adds contentions; because in “questions” the prevailing spirit is ambition; and, therefore, it is inevitable that they will immediately break out into “contention” and quarrels, for there everyone wishes to be the conqueror. This is accompanied by boldness in affirming things that are uncertain, which unavoidably leads to debates.

And fightings about the law. He gives this disdainful name to those debates that were raised by the Jews under the pretext of the law; not that the law itself produces them, but because the Jews, pretending to defend the law, disturbed the peace of the Church with their absurd controversies about observing ceremonies, about the distinction of kinds of food, and things of that nature.

For they are unprofitable and unnecessary. In doctrine, therefore, we should always consider usefulness, so that everything that does not contribute to godliness will be held in no esteem. And yet those sophists, in babbling about things of no value, undoubtedly boasted of them as highly worthy and useful to know; but Paul does not acknowledge them to have any usefulness unless they tend to the increase of faith and to a holy life.