After the seven thunders speak and John is told not to reveal what is said, he says that the mystery of God will be fulfilled, just as he announced to his servants the prophets. I think we can see some of this mystery later on. When this angel appears, it says he has a book in his hand. At this point in the chapter, John is given the book to eat. It tasted sweet as honey, but was poisonous or toxic and made John's stomach bitter. So, what happened here? A book has words in it that give some kind of information. It will not be the book as such that is toxic, but the words, or, to be more exact, what the words say. They also have to be toxic to John. This is John as a servant and prophet of God, so the words must be the opposite of the gospel. While love is vital, our gospel is one of repentance, obedience, and consequences. People would rather not face the difficult end because they are so attached to their wealth. That will lead tens of millions into hell. It makes my stomach bitter, and I have not eaten it.