Four Living Creatures
There are 2 angelic forms that the Bible calls "living creatures": cherubim and seraphim. Cherubim appear
to play a significant role: 1) one cherub guards the Tree of Life in the Garden of Eden from human beings
(Gen 3:22-24), 2) cherubim are an essential part of the Ark of the Covenant
made of gold at the two ends of the mercy seat (Ex 25:18-22), and 3) large
cherubim, up to 10 cubits in height, adorn the walls of the Holy of Holies
(1 Ki 6:19-35), which houses the Ark of the Covenant.
Ezekiel describes four living beings (Ezek 1:4-28) as having 4 faces
(human, lion, bull, and eagle), 4 wings, human hands, hoofed feet and gleamed as burnished bronze. These
creatures are flying about or flanking God's throne in heaven.
Ezekiel identifies these four living creatures as being cherubim
The Hebrew word "seraphim" is only found twice in the Bible, and in Isaiah's account
(Isa 6:2-6), the description of the seraphim matches that of Ezekiel's
cherubim (Ezek 1:4-28; 10:1-22).
Isaiah associates the seraphim as unceasingly praising the Lord (holy, holy, holy is the
Lord), hovering about the throne of God, or standing before Him. There is perhaps a suggestion that they serve
the heavenly court.
Because of this, it is believed that seraphim are a special group within cherubim.
The mention of "four living creatures" in Revelation 4:4-8 are likely
seraphim as they unceasingly praise the Lord about His throne.