The purpose of this letter is to the 1st century, not the 21st century. Peter is writing to them, not to you and I.

2 Peter 3:1-3 (NASB)
3 This is now, beloved, the second letter I am writing to you in which I am stirring up your sincere mind by way of reminder, 2 that you should remember the words spoken beforehand by the holy prophets and the commandment of the Lord and Savior spoken by your apostles. 3 Know this first of all, that in the last days mockers will come with their mocking, following after their own lusts,

THIS IS NOW: Peter is saying This is now! He's not writing to a future generation. It's NOW for them NOT you and I. Mockers came in the last days (the changing of ages) which was in the first century.

KNOW THIS FIRST: This is a sense of priority. And a priority does not mean 2,000 years! Peter is saying Hey! you better know this first. He's zooming in on something intended for the original 1st century audience. We cannot remove the original audience otherwise the priority is lost.

Let's say for example you have a job at a fast food restaurant, and there is a line around the building, and things are getting backed up. You've got people who have been waiting in line for 15 minutes, but there are people who are at the WINDOW and have paid, and have not even received their DRINKS yet! Imagine the manager takes charge and says OK EVERYONE, we've got a lot of work to do, there's people waiting in the line, it's wrapped around the building, but before we do ANYTHING ELSE, we've got to get the food out to the customer who has already paid, and hasn't even gotten their drinks. Get their drinks RIGHT NOW and the PRIORITY right now is THEM getting their food, so we can get this line moving.

Ok, so we see that a PRIORITY was called into view, in a ZOOMED-IN, immediately urgent and extremely important way. The rest of the work is also important, but now we have direction as far as what comes first, and things are no longer stagnant, or stuck.

Imagine if this thought played in your mind after your manager gave this instruction at your fast food job.

"This isn't intended for me, nor is it a priority relevant to anything concerning me, this is obviously for an employee who will one day work at a grocery store 2000 years in my future, and will be a DEFINITE priority for THEM 20 centuries from now!"

This is the type of absurdity that we have going on in the body of Christ, in regards to approaching the scriptures. We have no regard for the intended audience, or the original, first recipient of these texts, whom it was written TO all those years ago.

Futurists like to use 2 Peter 3:1-3 to close off all discussion when fulfilled prophecy disproves their doctrine.

Have fulfilled hope, instead of a delayed hope.

Hope that is delayed makes you sad, but a wish that comes true fills you with joy. (Proverbs 13:12)

We have a victorious king who has conquered all of his enemies. If not, what Kingdom is He king of?

Adapted in part from a friend.