We must remember that John's vision links time and eternity in ways that transcend human understanding. The Lord is not slow in keeping his promise, as some understand slowness. He is patient with you, not wanting anyone to perish, but everyone to come to repentance. But the day of the Lord will come like a thief. However, the final destiny of every human being begins the instant that individual dies.
Eternity is never more than a heartbeat away, never farther in the future than one's own death.
Blessed is the one who reads the words of this prophecy, and blessed are those who hear it and take to heart what is written in it, because the time is near. Do what it says. Again, we find John over-awed by the things the angel had revealed to him and as a result he began to worship God's messenger. This points to man's propensity to worship things or people other than God. The main emphasis is that God, who is the Creator of all that John had seen, is alone worthy of such worship.