Moreover, I will endeavour - I will leave such a permanent record of my views on these subjects that you may not forget them. He meant not only to declare his sentiments orally, but to record them that they might be perused when he was dead. He had such a firm conviction of the truth and value of the sentiments which he held, that he would use all the means in his power that the church and the world should not forget them.
After my decease - My "exodus," (ἔξοδον exodon;) my journey out; my departure; my exit from life. This is not the usual word to denote death, but is rather a word denoting that he was going on a journey out of this world. He did not expect to cease to be, but he expected to go on his travels to a distant abode. This idea runs through all this beautiful description of the feelings of Peter as he contemplated death. Hence he speaks of taking down the "tabernacle" or "tent," the temporary abode of the soul, that his spirit might be removed to another place 2-Peter 1:13; and, hence, he speaks of an "exodus" from the present life - a journey to another world. This is the true notion of death; and if so, two things follow from it:
(1) we should make preparation for it, as we do for a journey, and the more in proportion to the distance that we are to travel, and the time that we are to be absent; and,
(2) when the preparation is made, we should not be unwilling to enter on the journey, as we are not now when we are prepared to leave our homes to visit some remote part of our own country, or a distant land,
To have these things always in remembrance - By his writings. We may learn from this,
(1) that when a Christian grows old, and draws near to death, his sense of the value of Divine truth by no means diminishes. As he approaches the eternal world; as from its borders he surveys the past, and looks on to what is to come; as he remembers what benefit the truths of religion have conferred on him in life, and sees what a miserable being he would now be if he had no such hope as the gospel inspires; as he looks on the whole influence of those truths on his family and friends, on his country and the world, their value rises before him with a magnitude which he never saw before, and he desires most earnestly that they should be seen and embraced by all. A man on the borders of eternity is likely to have a very deep sense of the value of the Christian religion; and is he not then in favorable circumstances to estimate this matter aright? Let anyone place himself in imagination in the situation of one who is on the borders of the eternal world, as all in fact soon will be, and can he have any doubt about the value of religious truth?
(2) we may learn from what Peter says here, that it is the duty of those who are drawing near to the eternal world, and who are the friends of religion, to do all they can that the truths of Christianity "may be always had in remembrance." Every man's experience of the value of religion, and the results of his examination and observation, should be regarded as the property of the world, and should not be lost. As he is about to die, he should seek, by all the means in his power, that those truths should be perpetuated and propagated. This duty may be discharged by some in counsels offered to the young, as they are about to enter on life, giving them the results of their own experience, observation, and reflections on the subject of religion; by some, by an example so consistent that it cannot be soon forgotten - a legacy to friends and to the world of much more value than accumulated silver and gold; by some, by solemn warnings or exhortations on the bed of death; in other cases, by a recorded experience of the conviction and value of religion, and a written defense of its truth, and illustration of its nature - for every man who can write a good book owes it to the church and the world to do it: by others, in leaving the means of publishing and spreading good books in the world.
He does a good service to his own age, and to future ages, who records the results of his observations and his reflections in favor of the truth in a book that shall be readable; and though the book itself may be ultimately forgotten, it may have saved some persons from ruin, and may have accomplished its part in keeping up the knowledge of the truth in his own generation. Peter, as a minister of the gospel, felt himself bound to do this, and no men have so good an opportunity of doing this now as ministers of the gospel; no men have more ready access to the press; no men have so much certainty that they will have the public attention, if they will write anything worth reading; no men, commonly, in a community are better educated, or are more accustomed to write; no individuals, by their profession, seem to be so much called to address their fellow-men in any way in favor of the truth; and it is matter of great marvel that men who have such opportunities, and who seem especially called to the work, do not do more of this kind of service in the cause of religion. Themselves soon to die, how can they help desiring that they may leave something that shall bear an honorable, though humble, testimony to truths which they so much prize, and which they are appointed to defend? A tract may live long after the author is in the grave; and who can calculate the results which have followed the efforts of Baxter and Edwards to keep up in the world the remembrance of the truths which they deemed of so much value? This little epistle of Peter has shed light on the path of men now for 1,800 years (circa 1880's), and will continue to do it until the second coming of the Saviour.

Moreover, I will endeavor - And is not this endeavor seen in these two epistles? By leaving these among them, even after his decease, they had these things always in remembrance.
After my decease - Μετα την εμην εξοδον· After my going out, i.e. of his tabernacle. The real Peter was not open to the eye, nor palpable to the touch; he was concealed in that tabernacle vulgarly supposed to be Peter. There is a thought very similar to this in the last conversation of Socrates with his friends. As this great man was about to drink the poison to which he was condemned by the Athenian judges, his friend Crito said, "But how would you be buried? - Socrates: Just as you please, if you can but catch me, and I do not elude your pursuit. Then, gently smiling, he said: I cannot persuade Crito, ὡς εγω ειμι οὑτος ὁ Σωκρατης ὁ νυνι διαλεγομενος, that I AM that Socrates who now converses with you; but he thinks that I am he, ὁν οψεται ολιγον ὑστερον νεκρον, και ερωτα πως εδι με θαπτειν, whom he shall shortly see dead; and he asks how I would be buried? I have asserted that, after I have drunk the poison, I should no longer remain with you, but shall depart to certain felicities of the blessed." Platonis Phaedo, Oper., vol. i, edit. Bipont., p 260.

Moreover, I will endeavour,.... He signifies, that he should not only use all diligence to stir them up to, and put them in remembrance of the necessary duties of their calling while he was alive, but should make it his study to concert some measures, and take some steps,
that you may be able after my decease: or Exodus, meaning his going out of this world by death, in allusion to the Israelites going out of Egypt, and marching for Canaan's land; this world being, like Egypt, a place of wickedness, misery, and bondage; as heaven, like Canaan, a place and state of rest and happiness.
To have these things always in remembrance; by which they might be always put in mind of them, or by recurring to which they might have their memories refreshed; and what he means is, to leave these exhortations and admonitions in writing, which they might read, and be of use to them when he was dead and gone; and indeed by this, and his former epistle, though being dead, he yet speaketh.

endeavour--"use my diligence": the same Greek word as in 2-Peter 1:10 : this is the field in which my diligence has scope. Peter thus fulfils Christ's charge, "Feed My sheep" (John 21:16-17).
decease--"departure." The very word ("exodus") used in the Transfiguration, Moses and Elias conversing about Christ's decease (found nowhere else in the New Testament, but Hebrews 11:22, "the departing of Israel" out of Egypt, to which the saints' deliverance from the present bondage of corruption answers). "Tabernacle" is another term found here as well as there (Luke 9:31, Luke 9:33): an undesigned coincidence confirming Peter's authorship of this Epistle.
that ye may be able--by the help of this written Epistle; and perhaps also of Mark's Gospel, which Peter superintended.
always--Greek, "on each occasion": as often as occasion may require.
to have . . . in remembrance--Greek, "to exercise remembrance of." Not merely "to remember," as sometimes we do, things we care not about; but "have them in (earnest) remembrance," as momentous and precious truths.

That ye may be able - By having this epistle among you.