Creeds, Confessions, and Summary statements of Belief
The Confession of Peter
Some have opined that one of the earliest creeds is the famous moment when Jesus and his disciples were at Caesaria Phillippi, and Peter gave the so called “Good Confession”:
When Jesus came into the coasts of Caesarea Philippi, he asked his disciples, saying, “Whom do men say that I the Son of man am?” And they said, “Some say that thou art John the Baptist: some, Elias; and others, Jeremias, or one of the prophets.” He saith unto them, “But whom say ye that I am?” And Simon Peter answered and said, “Thou art the Christ, the Son of the living God.” And Jesus answered and said unto him, “Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.” Then charged he his disciples that they should tell no man that he was Jesus the Christ. (Matthew 16:13-20, King James Version)
In fact, this isn't only an ancient statement of faith. I have spent time in, and have a fondness for, a particular church that essentially uses a baptismal formula lifted from this passage. The baptismal candidate is asked to repeat “I believe that Jesus is the Christ, the son of the living God, and I take him to be Lord (or king) of my life.” (Ironically, this is also a church that would seriously make the claim that “we have no creed but Christ ”).
Jesus is Lord
One of the earliest creedal statements of the church following the death and resurrection of Jesus was “Iesous Kyrios” or “Jesus is Lord”. This phrase is seen in the New Testament in the writings of Paul. “Kyrios” is the Greek word for “master” or “lord”. To make this claim was bold indeed; As the early church emerged under the supremacy of the Roman Empire, it was required that people would say “Kyrios Kaisar". By acknowledging a different master than Caeser, by substituting the name of Jesus, one literally courted death.
The Old Roman Symbol and the Apostles Creed
The Apostles Creed is thought to be a very ancient formulation of faith, perhaps dating to the time of the 12 disciples. Here is the text of this creed. Saint Ambrose mentioned the Apostles Creed in about 390: "Let them give credit to the Creed of the Apostles, which the Roman Church has always kept and preserved undefiled" (Source)
A shortened version of it is the “Roman Symbol” or “Old Roman Creed”, which is mentioned by 2nd century authors such as Tertullian. A priest named Rufinus, writing in the year 400, expressed belief that this creed was written by the Apostles (Jesus original 12 disciples, minus Judas, of course) when they were gathered in Jerusalem.
A latin text and translation of the Roman Symbol can be found here.
The present form of the Apostles Creed was accepted in Rome and used by the Frankish ruler Charlemagne throughout his empire in the 9th century.
The Nicene Creed
This very early statement of the faith of the Christian Church was an expansion of the Apostles Creed, and aimed to defend against the heresy of Arianism. In a nutshell, Arius taught that Jesus was a created being, and not co-eternal with God. You can find more information here. This creed was initially devised in the Council of Nicaea in 325, and then revised and adopted at the Council of Constantinople in 381.
A later controversy arose regarding the insertion of the word filoque, "and the son", noted in brackets below. This has been a divisive point between Eastern Orthodox Christians and the Western churches. For more on this controversy, read here.
The Athanasian Creed
The Augsburg Confession
See Book of Concord site.