The Nicene Creed is not as old as the earliest form of the Apostles' Creed. Originally, it was written in AD325 at the First Council of Nicaea. It was updated in AD381 at the First Council of Constantinople. As a result, the Creed confessed today as the Nicene Creed is often referred to as the Niceno-Constantinopolitan Creed.
It was originally written to combat the Arian heresy. Arius was a preacher who taught that the Second Person of the Trinity (who later assumed human flesh and was born of the Virgin Mary as Jesus) was created by the Father, that there was a time when He was not. He denied the doctrine of the Trinity. The Nicene Creed (and the later revision) clearly teaches that the Second Person of the Trinity is truly God and always has been. God is indivisible, and has always been One God in Three Persons, a doctrine expounded in the Athanasian Creed.
The Athanasian Creed is confessed primarily during the Divine Service, the service at which the Sacrament of the Altar is celebrated.
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 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 Ghost 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 sitteth on the right hand of the Father; And he shall come again with glory to judge both the quick and the dead; Whose kingdom shall have no end.
And I believe in the Holy Ghost, The Lord and Giver of Life, Who proceedeth from the Father and the Son, Who with the Father and the Son together is worshipped and glorified, Who spake by the Prophets. And I believe one holy Christian1 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.