Biblical scholars hold that the second letter of Sr Peter is the latest in date of all books in the bible. It was probably written about AD150. But even here we are warned to stand up to false teaching; "be careful not to get carried away by the errors of unprincipled people."
One of the things we have to learn to do in the faith is to always return to the Church for sound teaching. We can so easily get carried away with our own ideas and we nearly always end up believing something that we should not. We find it so easy to rationalize.
"Think of our Lord's patience as your opportunity to be saved."
We make mistakes, God allows that. He gives us time to repent and to learn new ways of living and thinking, to drift away and come back to the fold. Indeed, says St Peter, we should "go on growing in grace and in the knowledge of the Lord." Oh - that is the proper use of our time and effort!