CHURCH congregations are used to reciting the Nicene Creed at eucharists with its clear statement about the divine nature of the Son. While this is a familiar part of our church life today, the text of this creed was accepted only after a long and bitter debate, which occupied most of the fourth century.

Then the Church had just emerged from a period of savage persecution to find itself the recognised faith of the vast Roman Empire, with the Emperor Constantine and his successors determined to bring unity to the Church and empire. There were varied influences on its thinking faith, mostly arising out of the rational philosophical approach of Plato and others, which resulted in the view of Arius that the Son could not be God in essence, but had to be a part of creation — albeit a perfect and unique being. A series of councils met, beginning at Nicaea, in 325, and leading to Constantinople, in 381, when the text of the creed was finally agreed.

Here we are told the story of this protracted and, at times, bitter process of discussion on the faith. There are the emperors, the councils, which met in many places, the bishops, and their supporters. The career of St Athanasius of Alexandria, whose writing was the basis of the credal statements about the Son, is described — with plentiful quotation — and also the three Cappadocian Fathers, St Basil, St Gregory of Nazianzus, and St Gregory of Nyssa, whose teaching extended to the person and work of the Holy Spirit. It is a complex story that is unscrambled, with people and places introduced and explained both in the text and in some helpful lists at the end of the book.

The discussion focused on the Greek term ousios, or substance, and asked whether the Son was of the same substance, homoousios, as the Father, or a similar substance, homoiousios, or just similar, homoios. The bishops chose the word homoousios to speak of the relation between Father and Son. While this is not a biblical word, it preserves the biblical message of the true God’s coming among us as a man and bringing salvation to a fallen world. It is not quite a definition — in spite of the book’s title — since God remains always unknowable; but it has given to the Church a language so that it can speak truthfully about our faith and guide us in our discipleship.
 

The Revd Dr John Binns is Visiting Professor at the Institute for Orthodox Christian Studies, Cambridge.

Defining God: Athanasius, Nicaea and the Trinitarian controversy of the fourth century
Patrick Whitworth
Sacristy Press £16.99
(978-1-78959-267-2)
Church Times Bookshop £15.29