Three Church Fathers Defended the Trinity

The fourth century was a perilous time for historic Christianity. Potent heresies that challenged the Christian view of God had arisen within the church. Theological dissenters denied the deity of the Son (Arianism) and the personality and deity of the Holy Spirit (Pneumatomachians or Macedonians). These heresies that rejected the divinity of the Son and Holy Spirit sought to undermine the historic Christian doctrine of the Trinity (from Tri-unity: one God in three persons).

Enter the Cappadocian Fathers
Three major Greek-speaking apologists for trinitarianism arose who are called the Cappadocian fathers.1 (Cappadocia was an area of Asia Minor [modern-day Turkey] where these Christian thinkers and authors primarily lived and ministered.) Two of these men were brothers and the third was a close friend. All three were students of classical culture and had been influenced especially by the third century theologian Origen of Alexandria. In large measure, the Cappadocian fathers worked to resolve the trinitarian controversy of that time. Let’s look briefly at these influential Eastern church leaders and note their contributions to the historic Christian doctrine of the Trinity.

Basil of Caesarea (c. 330–379)
Also known as St. Basil the Great, Basil was the practical leader of the three Cappadocian fathers, a teacher of rhetoric, and a voluminous author.2 He came from an affluent family, which afforded him a fine education in such important cities as Caesarea, Constantinople, and Athens. He studied Christian theology as well as the Greek arts and philosophy. Considered a man of action, Basil helped the poor and promoted and influenced the formation of monasticism. His preserved homilies on the first chapter of Genesis (the days of creation) are found in his Hexaemeron.

In his book On the Holy Spirit, Basil defends the Holy Spirit’s deity, one of the first apologetic works on behalf of the third person of the Trinity. Theologian Robert Letham explains Basil’s approach to the Trinity:

“The [Greek] terms ousia and hypostasis were used in various ways up to this point, often as synonyms. Basil proposed that ousia be reserved for the one being of God, while hypostasis be used for the way he is three. This gave the tools needed to consider how God is one in distinction from the way he is three.”3

Here’s Basil on the Trinity:

“Whence is it that we are Christians? Through our faith, would be the universal answer. And in what way are we saved? Plainly because we were regenerate through the grace given in our baptism. How else could we be? And after recognising that this salvation is established through the Father and the Son and the Holy Ghost, shall we fling away that form of doctrine?”4

Gregory of Nyssa (c. 335–c. 394)
Basil’s younger brother and disciple, Gregory, was considered the most intellectual of the three. He was drawn more to philosophy and theological speculation. He taught rhetoric and became the Bishop of Nyssa. He was a defender of orthodox doctrine.

Here’s Gregory of Nyssa commenting on how the Trinity doesn’t constitute three Gods:

“But in the case of the Divine nature we do not similarly learn that the Father does anything by Himself in which the Son does not work conjointly, or again that the Son has any special operation apart from the Holy Spirit; but every operation which extends from God to the Creation … has its origin from the Father, and proceeds through the Son, and is perfected in the Holy Spirit … Since then the Holy Trinity fulfils every operation in a manner similar to that of which I have spoken, not by separate action according to the number of the Persons, but so that there is one motion and disposition of the good will which is communicated from the Father through the Son to the Spirit (for as we do not call those whose operation gives one life three Givers of life, neither do we call those who are contemplated in one goodness three Good beings, nor speak of them in the plural by any of their other attributes); so neither can we call those who exercise this Divine and superintending power and operation towards ourselves and all creation, conjointly and inseparably, by their mutual action, three Gods.”5

Gregory of Nazianzus (330–c. 391)
Also coming from Cappadocian nobility, this Gregory studied in Athens where he met Basil. He became close friends with the two brothers and is considered one of the outstanding speakers and preachers in church history. He shared Basil’s interest in monasticism. Gregory is called “the theologian” in the Eastern church and he played a significant role in the Council of Constantinople (381).

Here’s Gregory of Nazianzus describing the Trinity:

“Such is my position, then, with regard to these questions. I hope it will always be my position, and that of whoever is dear to me; to worship the Father as God, the Son as God, and the Holy Spirit as God, three individualities, one divinity, undivided in honour and glory and essence and kingdom.”6

The Cappadocian fathers affirmed the Nicene orthodoxy of the Father and Son being homoousios (of one substance) and joined with it the Origenist view that the Father, the Son, and the Holy Spirit are three hypostases (persons). Of course, the Cappadocian fathers didn’t resolve all challenges regarding the Trinity. Properly preserving the tri-unity of God is a delicate balance that the church sought to define correctly over the early centuries. Theologian Tony Lane comments, “The Cappadocians greatly advanced the understanding of the Trinity in their time, but their conception of the unity of the Godhead needed to be strengthened.”7

Robert Letham puts it well:

“There is an enormous amount we can learn from the Cappadocians. As with all of us, there are also pitfalls in their thought that we should avoid. A critical but appreciative reading of these important theologians and churchmen will do a great deal of good in our own day.”8

Church history and historical theology contains much wisdom that can benefit today’s church. We as modern-day believers in Christ should deeply value the important lessons of the past.

Reflection: Your Turn 
Do you sing about the Trinity and hear the doctrine defined and defended in your church?


  • For an introduction to church history and historical theology via biography, see Kenneth Richard Samples, Classic Christian Thinkers.
  • For more on these three Eastern church fathers, see Anthony Meredith, The Cappadocians.


1. This article was influenced by Robert Letham, “The Three Cappadocians,” in Shapers of Christian Orthodoxy: Engaging with Early and Medieval Theologians, Bradley G. Green ed. (Downers Grove, IL: InterVarsity, 2010), chap. 5; and Tony Lane, A Concise History of Christian Thought (Grand Rapids, MI: Baker, 2006), “Cappadocian Fathers,” 36–39. 

2. Along with Cicero and St. Augustine, Basil is one of the most prolific authors of the ancient world. 

3. Letham, “The Three Cappadocians,” in Shapers of Christian Orthodoxy, 191.

4. Basil, De Spiritu Sancto (On the Holy Spirit), 10.26, in Nicene and Post-Nicene Fathers, trans. Blomfield Jackson, ed. Philip Schaff and Henry Wace, second series, vol. 8 (Buffalo, NY: Christian Literature Publishing Co., 1895), revised and edited for New Advent by Kevin Knight,

5. Gregory of Nyssa, On “Not Three Gods,” in Nicene and Post-Nicene Fathers, trans. H. A. Wilson, ed. Philip Schaff and Henry Wace, second series, vol. 5 (Buffalo, NY: Christian Literature Publishing Co., 1893), revised and edited for New Advent by Kevin Knight,

6. Gregory of Nazianzus, “Theological Orations 5: On the Holy Spirit,” in Five Theological Orations, trans. Stephen Reynolds (2011), 5.28.118,

7. Tony Lane, “Cappadocian Fathers,” in A Concise History of Christian Thought (Grand Rapids, MI: Baker, 2006), 38. 

8. Letham, “The Three Cappadocians,” in Shapers of Christian Orthodoxy, 230.