In the early years of Christianity, the Church Fathers commented extensively on numerology.
The Fathers repeatedly condemned the magical use of numbers which had descended from Babylonian sources to the Pythagoreans and Gnostics of their times. They denounced any system of philosophy which rested upon an exclusively numerical basis. Even so, they almost unanimously regarded the numbers of Holy Writ as full of mystical meaning, and they considered the interpretation of these mystical meanings as an important branch of exegesis. There was reluctance in the Christian teachers of the early centuries to push this recognition of the significance of numbers to extremes.
Irenaeus explains the number of the beast 666 (Apoc., xiii, 18) by the word "Lateinos". The numerical value of its constituent Greek letters yields the total
Also he discusses at length the Gnostic numerical interpretation of the holy name "Jesus" as the equivalent of 888, and he claims that by writing the name in Hebrew characters an entirely different interpretation is necessitated.
St. Ambrose commenting upon the days of creation and the Sabbath remarks,
Augustine of Hippo, replying to Tichonius the Donatist, observes that
Influenced mainly by Biblical precepts, the Fathers down to the time of Bede and even later gave much attention to the sacredness and mystical significance not only of certain numerals in themselves but also of the numerical totals given by the constituent letters with which words were written. An example is in the early Epistle of Barnabas. This document appeals to The Book of Genesis as mystically pointing to the name and self-oblation of the coming Messias.