The Nicene Creed
I believe in one God the Father Almighty, Maker of heaven and earth and of all things visible and invisible. And in one Lord, Jesus Christ the only begotten Son of God, begotten of his His Father before all worlds; God of God, Light of Light, very God of very God; begotten not made being of one substance with the Father, by whom all things were made. Who for us men and for our salvation came down from heaven and was incarnate by the Holy Spirt of the Virgin Mary and was made man. And was crucified also for us under Pontius Pilate. He suffered and was buried; and the third day He rose again according to the Scriptures; and ascended into heaven and sits at the right hand of the Father; and He shall come again with glory, to judge both the living and the dead; whose kingdom shall have no end.
And I believe in the Holy Spirit, the Lord and Giver of life, who proceeds from the Father; who with the Father and the Son together is worshipped and glorified; who spoke by the Prophets. And I believe in One, Holy, Catholic, and Apostolic Church: I acknowledge one baptism for the remission of sins; and I look for the resurrection of the dead and the life of the world to come. Amen.
During the third and fourth centuries major theological and doctrinial challanges arose just as the Church was breaking free from Roman persecution. The Church emerged in a Jewish, Greek and Roman world struggling to reconcile the relationship between the invisible universe of God and the visible world. The Church's struggle to find agreement on how to present the revelations of the personhood of God as received from Christ and recorded in the scriptures, reached its climax with the Arian controversy 290 - 452 A.D
Arius, an Alexandrian priest overly influnced by the teachings of Plato and the inconsistent character of the created world, presented a teaching that there was one God (Monos monotatos) "utterly alone one" who existed above all created things. This God created a mediator called the Logos (the Word or Christ) between himself and the created world (full of misery due to its inconsistency) the Logos became man, lead a perfect life which humans were to imitate and whose followers would receive a reward of eternal glory, but not union with God.
This teaching of Arius drove the distinctions of Christ and the Holy Spirit (being eternally present within the nature of God) outside of God. This "Arian" theory of one Supreme Being and two created and inferior deities destroyed the Holy Trinity and in effect made the very nature of Christ neither God or man. To address this ever growing threat the Church convened two Councils about 50 years apart and were attended by representatives of the major centers of Christinity in the city of Nicaea. These councils gave the Eastern and Western Churches a fourm to agree on the wording to be used in the form of a Creed, that would accurately present the personhood of the Trinity and the core beliefs of the Church.
The final wording of the second Council was ardently defended by the Cappadocian Fathers, St. Basil the Great, St. Gregory the Theologian (of Nazianzus) and St. Gregory of Nyssa and presented the scriptural definitation of the deity of the Son and Holy Spirit and their relationship with God as consisting of one substance (ousia) in three persons (hypostaseis). Thus all believers truly become one with God through the Son and partakers in God's own nature through their salvation in Christ. This same Nicene Creed remains to this day as the core expression of the Christian faith.