The Apostles' Creed is the earliest known Christian creed. It is believed to have its roots in what is known as the Old Roman Creed. The Old Roman Creed was the baptismal affirmation used in the Roman Church. The traditional claim is that the Apostles' Creed was the rule of faith given by the Twelve Apostles. It is more likely that the basic text was put together around the middle of the second century. While the Apostles themselves most likely did not write the creed as we have it, there are no elements in it that would have been unknown or rejected by them. Indeed, the creed itself was likely written as a summation of apostolic teaching. Its affirmations are quite basic.
The Apostles' Creed outlined the essentials that unified all Christians. The need to articulate such essentials was the result, not simply of diversity within the church, but the presence of heresies that needed to be refuted. Alister McGrath helpfully defines a heresy as an attempt at orthodoxy that has failed. The Creed effectively was a baptismal ritual in the form of question and affirmation:
Bishop: "Do you believe in God the Father Almighty, maker of heaven and earth?"
Convert: "I believe in God the Father Almighty, maker of heaven and earth."
Bishop: "Do you believe in Jesus Christ his only Son our Lord?"
Convert: "I believe in Jesus Christ his only Son our Lord. who was conceived by the Holy Spirit, born of the Virgin Mary, suffered under Pontius Pilate, was crucified, died, and was buried; he descended to the dead; the third day he rose from the dead and is seated at the right hand of God the Father Almighty; from thence he shall come again to judge the living and the dead."
Bishop: "Do you believe in the Holy Spirit?"
Convert: "I believe in the Holy Spirit; the Holy Catholic Church; the communion of saints; the forgiveness of sins; the resurrection of the body; and the life everlasting. Amen."
Three things should to be noted about the creed:
First, the Trinitarian structure of the creed is obvious. In the Great Commission in Matthew's Gospel (28:16-20), Jesus commands the disciples to baptize in the name of the Father, Son, and Holy Spirit. Again, the Trinitarian nature of God becomes crucial.
Second, of the three persons of the Trinity, the most commentary is devoted to Jesus. It is the narrative about Jesus which raises the Trinitarian issue in the first place and what forces the early Councils to discuss and debate. When the church makes the claim that Jesus is divine, then one must ask how the Son relates to the Father. Predicated from this are questions about the person of the Holy Spirit in relation to the Father and the Son. It must also be remembered that it is around the person and work of Christ that most heresies developed.
Third, the Apostles' Creed is the outline of the gospel story and the larger biblical narrative. "I believe in God the Father Almighty, maker of heaven and earth." This is a summary of Genesis 1 and 2, most specifically. It also includes the whole of the Old Testament, since it is the story of Israel who lives as the people that confess allegiance to the one, true God. "I believe in Jesus Christ his only Son our Lord..." This is the outline of the four Gospels. "I believe in the Holy Spirit..." outlines the story of the church as it begins in the Acts of the Apostles.
When we compare the Apostles' Creed to the Nicene Creed, we discover that the Nicene Creed fills out in greater detail several elements of the Apostles' Creed. This is so because there was a need to articulate the basic confession of the church in greater detail in response to debate, controversy, and heresy.