We 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 Son of God, the only-begotten, begotten of the Father before all ages. Light of Light; true God of true God; begotten, not made; of one essence with the Father, by whom all things were made; who for us men and for our salvation came down from heaven, and was incarnate of the Holy Spirit and the Virgin Mary, and became man. And He was crucified for us under Pontius Pilate, and 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 the living and the dead; whose Kingdom shall have no end.
Following the controversy about the Son of God, the Divine Word, and essentially connected with it, was the dispute about the Holy Spirit. The following definition of the Council in Constantinople in 381, which has come to be known as the second ecumenical council was added to the Nicene statement:
And [we believe] in the Holy Spirit, the Lord, the 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. In one Holy, Catholic, and Apostolic Church. I acknowledge one baptism for the remission of sins. I look for the resurrection of the dead, and the life of the world to come. Amen.
This whole Symbol of Faith was ultimately adopted throughout the entire Church. It was put into the first person form "I believe" and used for the formal and official confession.