Charles Ellicott Commentary Revelation 18:1

"After these things I saw another angel coming down out of heaven, having great authority; and the earth was lightened with his glory." — Revelation 18:1 (ASV)

And after these things . . .—Or, better, After these things (omit “and”) I saw another angel coming down, having great power (or, authority—entrusted to him for the work against Babylon); and the earth was illumined by (literally, out of) his glory.

The light that shines from the heavenly messenger shines like day upon the tawdry splendour of Babylon, and shows that what was admired was only worthless and corrupt. In his brief, but rousing call, he proclaims it to be so.