2 Peter 1:12

Wherefore I will not be negligent - That is, in view of the importance of these things.

To put you always in remembrance - To give you the means of having them always in remembrance; to wit, by his writings.

Though ye know them - It was of importance for Peter, as it is for ministers of the gospel now, to bring known truths to remembrance. Men are liable to forget them, and they do not exert the influence over them which they ought. It is the office of the ministry not only to impart to a people truths which they did not know before, but a large part of their work is to bring to recollection well-known truths. and to seek that they may exert a proper influence on the life. Amidst the cares, the business, the amusements, and the temptations of the world, even true Christians are prone to forget them; and the ministers of the gospel render them an essential service, even if they should do nothing more than remind them of truths which are well understood, and which they have known before. A pastor, in order to be useful, need not always aim at originality, or deem it necessary always to present truths which have never been heard of before. He renders an essential service to mankind who “reminds” them of what they know but are prone to forget, and who endeavors to impress plain and familiar truths on the heart and conscience, for these truths are most important for man.

And be established in the present truth - That is, the truth which is with you, or which you have received - Robinson’s Lexicon on the word πάρειμι pareimi. The apostle did not doubt that they were now confirmed in the truth as far as it had been made known to them, but he felt that amidst their trials, and especially as they were liable to be drawn away by false teachers, there was need of reminding them of the grounds on which the truths which they had embraced rested, and of adding his own testimony to confirm their Divine origin. Though we may be very firm in our belief of the truth, yet there is a propriety that the grounds of our faith should be stated to us frequently, that they may be always in our remembrance. The mere fact that at present we are firm in the belief of the truth, is no certain evidence that we shall always continue to be; nor because we are thus firm should we deem it improper for our religious teachers to state the grounds on which our faith rests, or to guard us against the arts of those who would attempt to subvert our faith.