Roman Catechism 2.5

Chapter 2 — Part I: The Creed — Introduction on Faith and the Creed

Section 5. The Creed — Now the chief truths which Christians ought to hold are those which the holy Apostles, the leaders and teachers of the faith, inspired by the Holy Ghost' have divided into the twelve Articles of the Creed. For having received a command from the Lord to go forth into the whole world, as His ambassadors, and preach the Gospel to every creature, they thought it advisable to draw up a formula of Christian faith, that all might think and speak the same thing, and that among those whom they should have called to the unity of the faith no schisms would exist, but that they should be perfect in the same mind, and in the same judgment.