Because you misinterpret one scripture (saying it says the angels continually desire to look into what was the mystery of Christ) and connect it with another one that isn't even about the gospel but the day and the hour.
you mishandle the text and "lol" because I disagree...wow
I did not mishandle the text, I'm starting to think you just don't want to see it.
jesus, in the flesh (according to the bible) said that the Angels don't know the day or the hour. Then, quite some time AFTER this, well after Jesus died, Peter wrote that the Angels are longing to look into the gospel.
the word for longing is, "epithumeo":
1937 epithyméō (from 1909 /epí, "focused on" intensifying 2372 /thymós, "passionate desire") – properly, to show focused passion as it aptly builds on (Gk epi, "upon") what a person truly yearns for; to "greatly desire to do or have something – 'to long for, to desire very much' " (L & N, 1, 25.12).
From epi and thumos; to set the heart upon, i.e. Long for (rightfully or otherwise) -- covet, desire, would fain, lust (after).
K, so the Angels long for and covet and lust after the chance to look into the gospel. Why? Why would they desire to look into something which has the sole purpose of demonstrating and showing how gods will was both fulfilled and will be fulfilled? You're saying they already know this, but the bible is showing that they know no more than we do, and the gospel was revealed to man, not Angels- as the word means they long to have, or covet, WHAT THEY DO NOT POSESS. They are just as involved as we are, because their "brothers" in heaven forsook their place and took to following the rebellion, they have their own test- will they choose the right side. It's not much of a test if they already know and have seen the outcome is it? Hence they long to look into gods word.