For a bishop ought to be blameless, as a governor of the house of God He again repeats, that they who aspire to the office of a bishop ought to retain an unspotted reputation; and he confirms it by this argument, that, because the Church is the house of God, every person who is appointed to govern it — is constituted, as it were, governor of the house of God. Now, he would be ill spoken of among men, who should take a scandalous and infamous person, and make him his steward; and therefore it would be far more base and intolerable to appoint such persons to be rulers of the household of God. The Latin word dispensator (steward or manager) — employed in the old translation, and retained by Erasmus — does not at all express Paul’s meaning; for, in order that greater care may be exercised in the election, he adorns the office of a bishop within this honorable eulogy, that it is a government of the house of God, as he says to Timothy,
“That thou mayest know how thou oughtest to conduct thyself in the house of the living God, the pillar and foundation of truth.”
(1 Timothy 3:15.) This passage plainly shows that there is no distinction between a presbyter and a bishop; for he now calls indiscriminately, by the latter name, those whom he formerly he employs both names in the same sense, without any distinction; as Jerome has remarked, both in his Commentary on this passage, and in his Epistle to Evagrius. And hence we may perceive how much greater deference has been paid to the opinions of men than ought to have been paid to them; for the language of the Holy Spirit, has been set aside, and the custom introduced by the arbitrary will of man has prevailed. For my own part, I do not find fault with the custom which has existed from the very beginning of the Church, that each assembly of bishops shall have one moderator; but that the name of office which God has given to all, shall be conveyed to one alone, and that all the rest shall be deprived of it, is both unreasonable and absurd. Besides, to pervert the language of the Holy Spirit — in such a manner that the same words shall have a different meaning from what he intended — is excessive and profane hardihood.
John Calvin, Commentary on Timothy, Titus, and Philemon, CCEL version, comments on Titus 1:7.