Artist’s 14th century portrayal of the third angel giving his message
(Wikipedia)

The 14th chapter of the Book of Revelation tells of messages from three angels. Are these messages from humans or three actual angels? Have these messages been going forth since the time of Jesus or are any or all of them for the future? Has Babylon fallen? What did leaders during the Sardis era teach about it? What did the Radio Church of God teach about the three angels messages? How about Herbert W. Armstrong? Will any respond to the warning of the three angels? Are the three angels' messages part of the final phase of the work? Should Philadelphia Christians support the preparation for the three angels to come now? Should Christians be separate from Babylon? Should Christians be supporting the work of proclaiming the gospel of the Kingdom of God? What is the position of the Continuing Church of God on many of these matters? Dr. Thiel addresses these and other matters in this sermon message.

Here is a link to a related article titled "Church of God on the Three Angels' Messages and 'Babylon'"

Youtube video link: The Three Angels’ Messages