Source: J.J. Collins, "The Sibylline Oracles," Jewish Writings of the Second Temple Period, ed. Michael E. Stone (Philadelphia: Fortress, 1984) 363.
"This passage refers to a conflagration, followed by a resurrection of the dead and a judgment. Even if this passage was part of the original oracle, that oracle was not necessarily Jewish. The ideas of conflagration and resurrection could be derived from Persian religion...Even the reference to the Flood in vs. 53 is not necessarily Jewish, since both the Greeks and Macedonians had traditions of a great Deluge. The description of the four empires itself contains nothing which is specifically Jewish. The oracle evidently looks forward to the fall of Macedonia, but is not motivated by any specifically Jewish grievance."
Collins is talking about Sibylline Oracle 4. The Sibylline Oracles have a lot of layers, as you can see: pagan, Jewish, and Christian. Sometimes, it's hard to tell what's what. Collins states in a footnote that some believe the phrase "Son of God" in the Oracles is a Jewish reference to the Temple rather than a Christian reference to Jesus. That strikes me as somewhat of a stretch, but it gives you a taste of the different ideas about this book.
People other than Jews and Christians had hope that a deity would end the present era of oppression and wickedness and inaugurate a new age of righteousness and peace. There are scholars who argue that the Jews borrowed such an idea from the Zoroastrians. Maybe. I don't know. Who says an idea has to be original to be right? Hope may very well be a part of the human condition, meaning it's not just a Jewish and Christian thing.
Collins' statement about the Flood is intriguing. I once had a professor who said that all these legends about the Flood were about a bunch of local floods, not a giant, cataclysmic inundation. I have a hard time believing that, since the legends often describe only a few survivors. We're dealing with more than the Nile flooding Egypt, since lots of people survived that!
Interestingly, two Columbia professors argue that there was a huge flood in the eastern hemisphere 7,600 years ago (see here). According to them, survivors managed to escape it and carried with them a memory of the great deluge, which made its way into their myths, legends, and religious traditions. The date doesn't exactly match Archbishop Usher's biblical chronology, but it acknowledges that something had to be behind all those flood stories.