John Calvin Commentary 2 Peter 1:12

"Wherefore I shall be ready always to put you in remembrance of these things, though ye know them, and are established in the truth which is with [you]." — 2 Peter 1:12 (ASV)

Wherefore I will not be negligent. Since it might seem that we distrust either the memory or the attention of those whom we often remind of the same thing, the Apostle makes this modest excuse: he did not cease to press upon the attention of the faithful what was well known and fixed in their minds, because its importance and greatness required this.

“You do, indeed,” he says, “fully understand what the truth of the gospel is, nor do I need to confirm, as it were, the wavering; but in a matter so great, admonitions are never superfluous, and therefore, they should never be considered troublesome.” Paul also uses a similar excuse in Romans 15:14:

“I am persuaded of you, brethren,” he says, “that ye are full of knowledge, so as to be able to admonish one another: but I have more confidently written to you, as putting you in mind.”

He calls that the present truth, which they had already come to possess through a sure faith. He then commends their faith, so that they might remain more firmly fixed in it.