Peter says in 2 Peter 1:12, So I will always remind you of these things, even though you know them and are firmly established in the truth you now have.
In lieu of the choice that we have in what manner we are going to enter Heaven, Peter feels compelled to remind his readers. We all need gentile reminders of how the choices we make in this life will affect us not only in this one but also the next.
There's much truth in saying that every man is the architect of his own fate. Your choices affect your destiny. Out of a rough block of stone one man may make a beautiful statue, and another, gravel. Both products are good and useful under certain conditions. But a statue can be immoral in conception, and gravel can be the grudging and punitive work of a criminal condemned to a rock pile.
The point is, whether you are a gifted artist or a competent gravel maker, you can choose whether to use your abilities worthily or unworthily. In building a Christian life you also have the same choice.