The Trinity

The trinity is the belief that God exists as three beings; The Father, The Son, and The Holy Spirit. Since the 4th century, the "Trinity" doctrine has existed in both the Eastern and Western sects of Christianity. With the Trinity belief, The Son is also believed to be two distinct beings; one divine and one human. The majority of christian sects believe in the trinity, but there are some groups that oppose trinitarianism; Binitarians, Unitarians, The Latter Day Saints (A.K.A. Mormons), and the belief in Modalism. The trinity, being such an important belief, however, the word "trinity" does not appear in the Old Testament or the New Testament. The official accpetance of the belief in the trinity was during the Council of Nicea in 325 A.D. (Peter Kreofsky)


Sources:
http://en.wikipedia.org/wiki/Trinity