Who do Christians believe God is? (part 2)

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In part 1 We set out the basics concerning the Trinity, namely how the doctrine is articulated. In part 2 we are going to delve into the details of how this doctrine came to be articulated as such.

The Details

Old Testament

If we are going to claim that Christ and Christianity are the fulfillment of the Messiah and His Kingdom promised in the Old Testament, then we must show that there is continuity between it and the New Testament. The goal here is not to prove the formulation of the previous section, but simply to show that the Old Testament reveals a single God, but also plurality within that single God.

A common argument for the Trinity from the Old Testament is to appeal to Deuteronomy 6.4, “Hear, O Israel: The LORD our God, the LORD is one” and say that “one” (echad) denotes composite oneness, and so the Trinity is compatible with the Old Testament. The word (yachid) would have more forcefully excluded the possibility of plurality within God and is not used to describe divine oneness.

This is not an altogether bad argument. Yachid is only used 12 times in the Old Testament and in those uses does mean “only, only one, solitary” and it is indeed never used to describe God. However, echad is used over 900 times in the Old Testament and has a wide range of possible meanings, including “only” (see Joshua 22.20; 1 Kings 4.19; Song of Songs 6.9; Zechariah 14.9). Furthermore, the clause in Deuteronomy 6.4 has no verb in Hebrew, which leaves us with at least 5 translation options:

  1. “Yahweh is our God; Yahweh is one.”
  2. “Yahweh our God, Yahweh is one.”
  3. “Yahweh our God is one Yahweh.”
  4. “Yahweh is our God, Yahweh alone.”
  5. “Our one God is Yahweh, Yahweh.”

So the argument is a plausible one, but due to the wide range of possible meanings with echad and the Hebrew syntax it is not the best.

What is unquestionably clear though from this text is that there is only one God: Yahweh.

What is also clear in the Old Testament is that there are multiple divine agents portrayed as coming from God, and thus being dependent on Him, but also as having an independent existence.


Sometimes in the Old Testament “wisdom” simply refers to the learned skill of human beings living in accordance with God’s commandments. Sometimes it refers to a primary attribute of God. But sometimes it is portrayed as a person with an existence apart from, yet dependent upon God. This independent, yet dependent existence is most evident in Proverbs 8.1-31, especially in verses 22-23:

“The LORD possessed me at the beginning of his work, the first of his acts of old. Ages ago I was set up, at the first, before the beginning of the earth.” (See also Psalm 104.24; Proverbs 3.19; Jeremiah 10.12)

In the New Testament this personification is applied to Christ by Paul in 1 Corinthians 1.24:

“but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God.” (See also 1 Corinthians 1.30; Colossians 2.3)

Most church fathers also interpret the Wisdom in Proverbs 8 to refer to Christ, (see Justin Martyr, Dialogue with Trypho, 61.129; Tertullian, Against Praxeas, 6; Origen, On First Principles, 1.2.1– 5, 8, 12), but some interpret it to refer to the Holy Spirit (e.g. Irenaeus, Against Heresies, 4.20.1, 3).

The Word of the Lord

The word of the Lord refers to God’s speech going out into the creation to accomplish His will. Sometimes this is to bring guidance, judgment, and salvation as in Isaiah 55.10-11:

“For as the rain and the snow come down from heaven
and do not return there but water the earth,
making it bring forth and sprout,
giving seed to the sower and bread to the eater,
so shall my word be that goes out from my mouth;
it shall not return to me empty,
but it shall accomplish that which I purpose,
and shall succeed in the thing for which I sent it.” (See also Psalm 119.89; 147.15-20).

Or to create the universe as in Genesis 1.1-2.2 and Psalm 33.6, 9:

“By the word of the LORD the heavens were made,
and by the breath of his mouth all their host…
For he spoke, and it came to be;
he commanded, and it stood firm.”

The Spirit of the Lord

The spirit of the Lord refers to God’s presence and power within the creation as seen in Psalm 139.7-10:

“Where shall I go from your Spirit?
Or where shall I flee from your presence?
If I ascend to heaven, you are there!
If I make my bed in Sheol, you are there!
If I take the wings of the morning
and dwell in the uttermost parts of the sea,
even there your hand shall lead me,
and your right hand shall hold me.”

It gives life, order, and beauty to creation (Genesis 1.2; Job 33.4; Psalm 104.30); will be present in the expected Messiah (Isaiah 42.1-3); and is portrayed as being the agent of a new creation (Ezekiel 36.26-27; 37.1-14). Thus it shows a strong correspondence with the New Testament and a Christian theology of the Holy Spirit.

Conclusion from the Old Testament

In the Old Testament then we see that there is only one God (Deuteronomy 6.4) and that there are multiple divine entities coming from that one God.

New Testament

There are 2 primary Trinitarian texts in the New Testament:

“Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit…” Matthew 28.19

“The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all.” 2 Corinthians 13.14

However, there are at least 115 more passages in which deity is attributed to at least one of the members of the Trinity. Some of these are discussed below.

Deity of the Father

The deity of the Father isn’t in dispute, but nevertheless it is affirmed in the New Testament in numerous places, some of which include: John 20.17; Romans 1.7; 1 Corinthians 1.3, 8.6, 15.24; 2 Corinthians 1.2-3, 11.31; Galatians 1.1, 3, 4; Ephesians 1.2-3, 17; Philippians 1.2, 2.11; Colossians 1.2-3, 3.17; James 1.27; 1 Peter 1.2-3; 2 Peter 1.17; 2 John 3; Jude 1.

Deity of Jesus

There are numerous passages that attribute deity to Jesus, but among the most important are what are called the “high Christological passages.” They include John 1.1-18; Romans 1.2-5; Philippians 2.6-11; Colossians 1.15-23; Hebrews 1.1-14; 1 John 1.1-3.

Deity of the Holy Spirit

The deity of the Holy Spirit is not as obvious as that of the Father and the Son, and so some explanation of the various passages will be necessary.

Sometimes the Holy Spirit is used interchangeably with God as in Acts 5.3-4 where in v.3 Peter rebukes Ananias and said he has lied to the Holy Spirit, and then in v.4 says he has lied to God. Or again in Acts 28.25-27 where Paul says the Holy Spirit spoke through Isaiah and then quotes Isaiah 6.9-10, but Isaiah speaks after hearing “the Lord” (adonai). Or yet again in Hebrews 10.15-17 where the author says “The Holy Spirit also bears witness to us…” and then quotes Jeremiah 31.33-34, but Jeremiah declares the words of Yahweh, thus equating the Holy Spirit with Yahweh.

The Holy Spirit possesses the attributes of God, such as: knowing the thoughts of God (1 Corinthians 2.10-11; John 16.13).

The Holy Spirit possesses the power of God. This can be seen in the virgin birth (Luke 1.35); Paul’s ministry accomplishments (Romans 15.19); convicting the world (John 16.8-11); and spiritual regeneration (John 3.5-8; Titus 3.5), a power which Jesus said belongs to God (Matthew 19.16-26). The Holy Spirit is eternal like the Father and the Son (Hebrews 9.14).

The Holy Spirit is associated with the Father and the Son as an equal in Matthew 28.19 and 2 Corinthians 13.14.

Conclusion from the New Testament

The result of all these verses is the same as the Old Testament: one God, but multiple divine entities coming from that one God.

Patristic Development

The Arian Controversy

It was during the Patristic period (roughly from 100A.D.- 600A.D.) that the doctrine of the Trinity we know today came about (see part 1). As should be clear from the Biblical data above the theologians of this period were not developing the doctrine in the sense of inventing something new, but were developing in the sense of putting into a clear and precise model how God revealed Himself both in Scripture and in reality.

This development came about in part because various heresies arose which taught something different from what the Apostles handed down and in part because Gentiles (mainly Greeks) cared a great deal more about metaphysics than Jews. For the most part the Jewish Christians seemed to be content with considering Jesus to be the fulfilment of the Messiah they expected from OT prophecies. The Gentile Christians however were not content to simply think of Jesus in this manner. Add to this the aforementioned rise of heresies (e.g. Arianism) and it eventually became necessary for the entire Church to agree on a certain articulation and description of God in order to maintain unity and order in the Church.

Primarily the doctrine of the Trinity was defined at Nicea in 325 in response to the heretical Arian view. Arius, who was a bishop in the early church, believed in two different second persons of the Trinity, what are referred to as two logoi. One of these logoi was eternal and uncreated. The second was created by the Father from nothing. Now this second logoi was, to be sure, the most prominent of every creature due to being directly created by God from nothing, but he was not God by nature. Rather, he had the dignity of being called “the son of God” bestowed on him as a result of his (foreseen) righteousness. So Arius essentially had one fully divine second person of the Trinity and one created second person of the Trinity, thus he denied that Jesus was God in the flesh (i.e. God incarnate). Jesus rather “earned” his divinity.

Arius’ main opponent was Athanasius who argued that if Jesus was not God incarnate then humanity was not redeemed from sin and death since this was something that was only possible for God to do. I invite you to read his book On The Incarnation for his full argument in all its particulars. It is really quite a good work.

Eventually the council of Nicea in 325 became known as the 1st Ecumenical Council and it articulated the Trinity to be one ousia (οὐσία), three hypostases (ὑπόστασις). In the East (e.g. Greece and eastward) this doctrine caused all sorts of problems because the two terms (ousia and hypostasis) are synonyms, so the result of Nicea in the East was all sorts of confusion. It took quite a while to actually get the East all on the same page and to understand what exactly the doctrine of Nicea was saying, but eventually they were able to do so.

If you are interested in all the details concerning Nicea and the resulting confusion in the East there are two books I would recommend: J.N.D Kelly, Early Christian Doctrines and Leo Donald Davis, The First Seven Ecumenical Councils. Kelly is the harder to read of the two, but it is probably the one I would recommend because it has more of the theological details and beliefs of the various factions involved. It is quite a dense read, so be sure to take it slow and easy as you read. Davis is also good, but it is more historically focused than Kelly, so you lose a lot of the theological details. However, Davis is the easier one to read I think.

For the most part the West (e.g. Italy and westward) had little issue accepting this verbiage because they read ousia as substantia and hypostasis as persona and could easily make a distinction between the two terms. Tertullian, one of the most formative and influential theologians in Western Christianity, is likely responsible for the development of this distinctive Trinitarian terminology that we still use today. He invented the term Trinity (Trinitas), used the term Person (Persona) to translate the Greek hypostasis (usually translated “substance” or “essence”), and used the term Substance (Substantia) to express the fundamental unity within God, that is, what the members of the Trinity have in common (i.e. to translate ousia). Scholars debate what Tertullian meant by Person. The Greek term refers to the basic nature or structure of an entity, but the Latin Persona literally means “a mask,” such as one worn by an actor in a Roman drama. It is possible by using this term that Tertullian wanted his readers to understand the idea of “one substance three persons” to mean that the one God played three distinct yet related roles in the great drama of human redemption.

By the second half of the fourth century it had been concluded that the Father and Son were of one substance, thus condemning the Arian view as heresy and establishing a consensus within the church (although Arianism itself didn’t go away and still remains today, e.g. Jehovah’s Witnesses). The view of Nicea was again affirmed by Constantinople I (381) and the decisions of these two councils produced what is now called the Nicene Creed. What was not settled however is the relationship between the Father and the Spirit. Western theology has tended to begin from and emphasize the unity of God, but Eastern theology (found in the Eastern Orthodox churches, e.g. Greek Orthodox, Russian Orthodox, etc) has tended to emphasize the distinct individuality of the three persons. The Eastern approach could logically lead to three independent beings doing quite different things, but two later developments: perichoresis and appropriation excluded this possibility.

The Filioque Controversy

These two different tendencies were bound to conflict and eventually exploded in 1054 with the Western church and Eastern church anathematizing one another over the addition of “and the Son” (Filioque) to the Nicene Creed. Originally the Nicene Creed said the Holy Spirit proceeds from the Father only, but later the West added “and the Son” so that the Holy Spirit proceeded from both the Father and the Son. For the West this didn’t cause much of a problem theologically due to its emphasis on the unity of God. However, this was (and remains) a huge problem for the East because in order to safeguard the unity of God against their emphasis on the distinctness of the three persons they stress that both the Son and the Spirit proceed from the Father, thus the unity is found in the Father, who is the “Fountainhead of Divinity.” So in their view if you have the Spirit proceeding from both the Father and the Son you have denigrated the Spirit and have created two Gods (the Father and the Son) thus destroying the unity and equality between the persons of the Trinity.

Perichoresis and Appropriation

The term perichoresis is often found as “mutual interpenetration” in English. It refers to the mutual indwelling of the members of the Trinity in one another, but still maintains the individuality of each of them. Logically following from this idea is appropriation, which responds to the modalist heresy. Modalism argued that at different points in the redemption of humanity God existed in different “modes” of being. So at one point God was Father and created the world, and then at another God was Son and redeemed it. Against this, appropriation insists that the works of the Trinity are a unity; whatever one does, the other two members do as well, a logical extension of their mutual indwelling. A helpful image for grasping these two concepts might be a dance, where each member maintains their individuality, but is involved in whatever another member does.


Simply put, the doctrine of the Trinity is an accurate articulation of what God has revealed about Himself as recorded in Scripture. God has revealed Himself to be one, but also to have multiple “entities” coming from this one God. There are many things that we do not understand about the Trinity, but we must try to grasp and understand what we do know. It is not an invented doctrine. It is a doctrine that was birthed through struggles against various heresies in the early years of the church in order to combat these heresies and give a proper articulation of the Christian faith.

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Tom Ferguson ThM 2018, Dallas Theological Seminary