A Catholic Catechism identifies the current theological beliefs of the Church, both the dogmatic (required belief for all times) and the decreed beliefs (required until changed). Only two official Catechisms have ever been published by the Catholic Church: the Trent Catechism in the 16th century; and the Vatican II Catechism published in the twentieth century. They follow the same four-part layout scheme; Profession of Faith (Apostles’ Creed), Celebration of the Christian Mystery (The Sacraments), Life in Christ (The Ten Commandments), and Christian Prayer (The Lord’s Prayer). While it is sometimes difficult to distinguish between the required beliefs and suggested beliefs, the Catechism provides extensive footnotes and comments enabling the attentive reader to make such a distinction.
With over two thousand years of history behind it, why has the Church issued only two official Catechisms? And those two only in the past five hundred years? Well the truth of the matter is, another Catechism was published in the third century and recognized as the most comprehensive set of beliefs at the time–well researched with contributions from many bishops throughout the Christian world. It was called De principiis and written by Origen, the director of the Catechetical Schools of Alexandria and Caesarea, the finest Christian schools known to man up to that time and for some time afterwards.
Origen’s work was not an official document of the Christian Church for two reasons. The most basic reason is that the Church had not held a Ecumenical Council–a gathering of the bishops of the world–until the fourth century so it could not have been considered recognized as such by the “Church.” Secondly, several of Origen’s suppositions within De principiis had subsequently been rejected by the Vatican and large numbers of bishops even before the first Ecumenical Council. Nevertheless, the subject matter within Origen’s work has been and is still being studied within seminaries up to the present time for its early description of dogmatic beliefs as passed on from the lips of Jesus Christ to his apostles.
A more comprehensive discussion of Origen’s work is found in my novel The Scholar’s Challenge. I also cover the need for and writing of the first official Catechism in my novel The Hidden Saint: The Sixteenth Century Church in Crisis. I think you will enjoy both novels.