The Great Catechetical Oration (or Address on Religious Instruction) is perhaps the most successful work of St. Gregory of Nyssa (335 - 395 A.D.). In it, he gives a systematic overview of theology in miniature, laying out the Christian view of how human nature, lost from the fall of Adam, has been restored to the image of God. The work is divided into three parts 1) The Trinity, 2) The Reasonableness of the Incarnation, 3) The Sacraments.
The text for this book is from "Gregory of Nyssa: dogmatic treatises, etc.," New York: Christian Literature Co., 1893, translated by H. A. Wilson (1854-1927). The original footnotes are preserved along with the Bible references. This version is also illustrated with artwork from the middle ages and the renaissance period, which depict points expounded upon in the catechism.

"Gregory of Nyssa: dogmatic treatises, etc.," New York: Christian Literature Co., 1893, translated by H. A. Wilson (1854-1927)