Let's hear Calvin's take on the verse...
This explanation contains a true, godly, and useful doctrine, that then only are the prophecies read profitably, when we renounce the mind and feelings of the flesh, and submit to the teaching of the Spirit; but that it is an impious profanation of it when we arrogantly rely on our own acumen, deeming that sufficient to enable us to understand it, though the mysteries contain things hidden to our flesh, and sublime treasures of life far surpassing our capacities. And this is what we have said, that the light which shines in it, comes to the humble alone. But the Papists are doubly foolish, when they conclude from this passage, that no interpretation of a private man ought to be deemed authoritative. For they pervert what Peter says, that they may claim for their own councils the chief right of interpreting Scripture; but in this they act indeed childishly; for Peter calls interpretation private, not that of every individual, in order to prohibit each one to interpret; but he shews that whatever men bring of their own is profane. Were, then, the whole world unanimous, and were the minds of all men united together, still what would proceed from them, would be private or their own; for the word is here set in opposition to divine revelation; so that the faithful, inwardly illuminated by the Holy Spirit, acknowledge nothing but what God says in his word. However, another sense seems to me more simple, that Peter says that Scripture came not from man, or through the suggestions of man. For thou wilt never come well prepared to read it, except thou bringest reverence, obedience, and docility; but a just reverence then only exists when we are convinced that God speaks to us, and not mortal men. Then Peter especially bids us to believe the prophecies as the indubitable oracles of God, because they have not emanated from men's own private suggestions. 20. Knowing this first - Here Peter begins to shew how our minds are to be prepared, if we really wish to make progress in scriptural knowledge. There may at the same time be two interpretations given, if you read ἐπηλύσεως as some do, which means occurrence, impulse; or, as I have rendered it, interpretation, ἐπιλύσεως. But almost all give this meaning, that we ought not to rush on headlong and rashly when we read Scripture, confiding in our own understanding. They think that a confirmation of this follows, because the Spirit, who spoke by the prophets, is the only true interpreter of himself.
Outside of some evangelical/fundamentalist cults, Calvin and his ilk have been relegated to the dustbins of history where his infamous legacy is continuously evidenced by the perpetual fractionizing processes. This is the historical curse that he has bequeathed his disillusioned followers.
Calvin has been marginalized and rightly so in modern times. since he did precious little in the furtherance of spreading the word of God but the boy did sow the seeds of hatred and corruption.
God bless
AMEN! AMEN!