The Catechism in Questions & Answers

31. How did the first Christian creeds come into being?

The first Christian creeds are called the “early church creeds”. They came into being between the second and fourth centuries AD. It was during this time that the doctrine of the trinity of God and the doctrine of the essence of Jesus Christ, that is, of His nature, were formulated.
This had become necessary because there had been disputes about various contents of faith. For example, there was the opinion that Jesus Christ did not really die on the cross and that He did not really resurrect. The function of the creeds was to distinguish the faith from these heresies.