FourAnimals. The symbolical animals of the vision of Ezekiel (the Mercabah). “ With the first Christians the celebration of the Mysteries of the Faith was accompanied by the burning of seven lights, with incense, the Trishagion, and the reading of the book of the gospels, upon which was wrought, both on covers and pages, the winged man, lion, bull, and eagle” (Qabbalah, by Isaac Myer, LL.B.). To this day these animals are represented along with the four Evangelists and prefixing their respective gospels in the editions of the Greek Church. Each represents one of the four lower classes of worlds or planes, into the similitude of which each personality is cast. Thus the Eagle (associated with St. John) represents cosmic Spirit or Ether, the all-piercing Eye of the Seer; the Bull of St. Luke, the waters of Life, the all-generating element and cosmic strength ; the Lion of St. Mark, fierce energy, undaunted courage and cosmic fire; while the human Head or the Angel, which stands near St. Matthew is the synthesis of all three combined in the higher Intellect of man, and in cosmic Spirituality. All these symbols are Egyptian, Chaldean, and Indian. The Eagle, Bull and Lion-headed gods are plentiful, and all represented the same idea, whether in the Egyptian, Chaldean, Indian or Jewish religions, but beginning with the Astral body they went no higher than the cosmic Spirit or the Higher Manas—Atma-Buddhi, or Absolute Spirit and Spiritual Soul its vehicle, being incapable of being symbolised by concrete images.
Source: H.P.Blavatsky - The Theosophical Glossary