Wherefore I will not be negligent to put you always in remembrance of these things, though ye know them, and be established in the present truth.
Wherefore - as these graces are so necessary to your abundant entrance into Christ's kingdom (2 Peter 1:10-11).
I will not be negligent. 'Aleph (') A B C, Vulgate, read х Melleesoo (G3195)], 'I will be about always to put you in remembrance' (an accumulated future): I will regard you as always needing to be reminded (cf. 2 Peter 1:15).
Always - why he writes the second letter so soon after the first: there is likely to be more and more need of admonition on account of the increasing corruption (2 Peter 2:1-2).
In the present truth - the Gospel truth: formerly promised to Old Testament believers as about to be, now in the New Testament actually with, and in, believers, so that they are "established" in it as a "present" reality. Its importance renders frequent monitions never superfluous (cf. Romans 15:14-15).