In the book of Revelation, the word "angel" is used
for different kinds of persons. It can refer to good
angels or bad angels, even to Jesus Christ, Himself.

They may be identified by their descriptions. This
follows the rule that when Christ is mentioned,
some portion of the first chapter is repeated. There
is added the rainbow which was around the throne.
The rainbow is the sign of God's purpose to redeem,
not to destroy the world and the human race.