What does this verse reveal about the identity of the Lord?

Revelation 4:8 (ESV)

8 And the four living creatures, each of them with six wings, are full of eyes all around and within, and day and night they never cease to say, “Holy, holy, holy, is the Lord God Almighty, who was and is and is to come!”

This God is master (“the Lord”), sovereign (“the Almighty”), and eternally reliable (“who was and is and is to come”). On the latter expression see on Revelation 1:4, Revelation 1:8.