1 Peter 1:10-12

Concerning this salvation, the prophets who prophesied about the grace that was to be yours searched and inquired carefully, inquiring what person or time the Spirit of Christ in them was indicating when he predicted the sufferings of Christ and the subsequent glories. It was revealed to them that they were serving not themselves but you, in the things that have now been announced to you through those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look.

1 Peter 1:10-12

This salvation is a really big deal.  A long time ago, the prophets prophesied about  this salvation.  They were the ones who "searched and inquired carefully" regarding who and when this was to happen.  In fact, all of that wasn't even for their own sake but for believers like Peter's readers.  It is even something that "angels long to look (into)".  This very thing that the prophets prophesied for the sake of believers many years later and something that even angels long to look into is what believers have.  This is important and a big deal.