It puts the Book of Revelation in its proper historical context and analyzes how religious and political leaders have used it to create fear for their own benefit, for centuries. Here are a couple reviews from Amazon:
Ehrman does it again. He has taken the most incomprehensible work to have found its way into the New Testament and, putting into the context of its day, opened it up for us. Behold the materialistic believers guide to the end of times, a seemingly unfathomable fantasy in which Jesus is recast as the avenger, a true super antihero hellbent on destroying all who fail to believe in him, but offering gold, jewels, comfort and luxury to his slaves
for eternity on Earth. No longer a believer, Ehrman takes great pains to show us why the early Church Fathers were right to reject John of Patmos materialistic, vengeful, sickeningly cruel and violent fantasy. By comparing the Jesus of the gospels to that of Revelation, he makes an irrefutable case for rejecting the latter. Despite being a non-believer, Ehrmans deep respect for the true message of Christianity makes this book not only acceptable but also a must read for Christians and atheists alike.
Just as Dr. Ehrman has challenged conventional Christian beliefs in his previous books through his extensive biblical scholarship, in Armageddon he reveals the actual message of Revelation. Ehrman explains that the author of Revelation was writing in apocalyptic style about the destruction of the Roman empire and his belief in its replacement by a Christian empire of domination, revenge and destruction. Maybe most importantly, Ehrman shows how the message of Revelations author contradicts Jesuss message as described in the four Gospels. Once again, through his extensive scholarship and expertise, Dr. Ehrman illustrates the very human nature of the Bible, a collection of writings often by anonymous authors and some even forgeries that often contradict each other.
Here's a link to the transcript of an interview with Ehrman for Fresh Air on NPR:
https://www.npr.org/2023/04/03/1167715957/armageddon-shows-how-literal-readings-of-the-bibles-end-times-affect-modern-time