The Trinity is the one God in three persons, Father, Son and Holy Spirit.

The Revelation of the Trinity

The revelation of the one God

The existence of the one God has been known to faith and reason throughout history. God chose to reveal himself as one Lord to the people of Israel, to teach them that he is the creator of all things and the single, true and exclusive object of worship. However, the Old Testament gives glimpses of personal distinctions in the one God. An example is the use of the plural pronoun ‘us’ at the creation of human beings.

Then God said, “Let us make man in our image, after our likeness.” Genesis 1:26

The revelation of the three persons

In the New Testament, when God the Son becomes man, he openly reveals the persons in God. First the relationship between Father and Son is revealed:

“No one has ever seen God; the only Son, who is in the bosom of the Father, he has made him known.”

He then reveals the relationship of the Father and the Son with the Holy Spirit:

“When the Paraclete comes, whom I shall send to you from the Father, the Spirit of truth who issues from the Father, he will be my witness.” John 15:26

All Christian life begins with Baptism in the singular name of the three divine persons, following Jesus’ command:

“Make disciples of all nations; baptise them in the name of the Father and of the Son and of the Holy Spirit.” Matthew 28:19-20

The three divine persons are the One Triune God.

The Trinity in Creed and worship

The Trinity is the source and centre of the Christian faith. The divine persons introduce each section of the Creed.

I believe in God, the Father Almighty.
I believe in Jesus Christ his only Son, our Lord.
I believe in the Holy Spirit.

What is the Trinity?

One substance, three persons

God alone reveals the doctrine of the Trinity. Human reason can know that there is a God; we cannot know God as he knows himself except from what God has revealed. The fact that Jesus Christ reveals the relationship of Father, Son and Holy Spirit, tells us that these are distinct divine persons. Each divine person can properly say ‘I’, as when Jesus says “I and the Father are One” (John 10:30). Jesus also uses a masculine personal pronoun (translated ‘he’) of the Holy Spirit when he says, “the Counsellor, the Holy Spirit, whom the Father will send in my name, he will teach you all things” (John 14:26).

Nevertheless, the relations within the Trinity differ from those among human persons. Our relations are changeable, and established over time. By contrast, the relations of the divine persons are the very being or ‘substance’ of God. They are eternal and unchanging. This oneness of being, along with the distinction of divine persons, is expressed in the Trinitarian formula affirmed by the early Church:

The Trinity is one substance, three persons.

Mistaken beliefs about the Trinity

Modalism denies that the Father, Son and Spirit are three persons, and sees them as mere appearances, or masks, of one person. Tri-theism denies that there is one God, and claims that the Father, Son and Spirit are three gods. Subordinationism denies that the Son and the Spirit are equal in divinity to the Father, claiming that they are subordinate to him.

The Trinity and our friendship with God

God does not want us to relate to him merely as creatures to their Creator, but to enjoy intimate friendship with him by sharing the divine life of the Trinity. This is why all Christian belief is Trinitarian (for example, the Creed); all sacraments are Trinitarian (for example, Baptism in the name of the Trinity); all Christian life is directed towards union with the Trinity (for example, the virtue of charity) and all Christian prayer is Trinitarian (for example, the Sign of the Cross).

This article is originally from ‘CREDO: The Catholic Faith explained’ by CTS.