The Holy Trinity is a mystery that is beyond our finite human understanding. By definition, the term, “mystery” refers to something that is hidden, unknown, incomprehensible, or which has not been yet explained or understood (Cambridge Dictionary, n.d.).  The Catechism of the Catholic Church speaks of how the central mystery of the Catholic Faith, is that of the Holy Trinity Himself – the mystery of GOD, and hence the origin of all other mysteries (CCC. 234). While GOD has left traces and clues in Creation about the identity of the Holy Trinity, the mystery of the Holy Trinity remains a mystery of Faith that may only be revealed by God Himself. (CCC. 237). Yet, in the person of Jesus, the Father is revealed. As Jesus says in Matthew 11: 27, “No one knows the Son except the Father, and no one knows the Father except the Son and anyone to whom the Son chooses to reveal Him.” In Matthew 28:19, Jesus speaks explicitly about the Holy Trinity and commissions His disciples with the words, “Go therefore and make disciples of all nations, baptising them in the name of the Father and of the Son and of the Holy Spirit.” In John 14: 8-21, we are given insight into the discourse of the Holy Trinity by Jesus: “Do you not believe that I am in the Father and the Father is in me? The words that I speak to you I do not speak on my own. The Father who dwells in me is doing his works. Believe me that I am in the Father and the Father is in me, or else, believe because of the works themselves.” (John 14:10-11); “And I will ask the Father, and he will give you another Advocate to be with you always, the Spirit of truth, which the world cannot accept, because it neither sees nor knows it. But you know it, because it remains with you, and will be in you.” (John 14: 16-17)

The issue is that humanity wants to know and wants answers. Some modern clergy persons in an attempt to appeal to the populace have spoken about the Holy Trinity in ways that are pedestrian and even to the point of bordering upon heresy, comparing the Holy Trinity to things like three-in-one coffee or Milo. Nonetheless, the Church is no stranger to battling heresy.

The first heresy: The unity of the Holy Trinity is denied. This leads to seeing the Holy Trinity as existing as three different gods, but united by some sort of philosophy or divine essence. This is tritheism – the false belief that the Holy Trinity is made up of different deities but united in some moral belief.

The Nicene Creed, written after the First Council of Nicaea, convened in A.D. 325 was meant to address this, with the words, “We believe in one God…” The Nicene Creed also addresses the Arian and Gnostic heresies. At the First Council of Nicaea, all the bishops agreed except five, including Arius. They were then excommunicated and exiled and all the writings by Arius were burnt (Vanderbilt University, n.d.).

The second form of heresy: The distinct identities of three persons in One God is denied. This is found in the Monarchianism heresy that positions the Holy Trinity as having no real and distinct personhood, but that there is only a rational distinction among them – something that is only thought of in the mind and the intellect. While the Modalism heresy defines the Holy Trinity as existing in different modes – The false belief is this: Holy Trinity is one person but takes on different roles and wears different faces or modes, or masks in those different roles.

Adoptionist Monarchianism takes this heresy further, by saying Jesus was a mere man, who was adopted by God at his baptism at the Jordan.

The  Catholic doctrine of the Three Distinct persons in One God is also denied in the heresy of Subordinationism: those holding this position deny the true divinity of the Second and Third Persons, who are claimed to be creatures and are subordinated to the first person who alone is really God. Subordinationism accepts the notion of three Persons in God, but denies the consubstantiality of the Son and the Holy Spirit with the Father, and therefore their true divinity. In this erroneous thinking, Jesus and the Holy Spirit are but mere creatures produced by the First Person. Some proponents of this error state that the Father created the Son, and the Son created the Holy Spirit. The main proponents of this view were the priest Arius and his followers in the 4th century. The Council of Nicaea in  A.D. 325, the First Ecumenical Council, was convened to eradicate this error. Those who denied the divinity of the Holy Spirit in the second half of the 4th century were called Macedonians after Bishop Macedonius who was excommunicated in the year 360. (International Catholic University, n.d.)

Modern heresies include: preaching about the Holy Trinity by saying that God the Father, is only the God of the Old Testament, when in actuality, God that we see in the Old Testament is the same God that is incarnate in Jesus in the New Testament; saying that the Holy Spirit is not a person but a force, or as God’s actions in the world – God the Father, person, Jesus, person, Holy Spirit, force. This is erroneous teaching.

Another ancient controversy, was the issue of the filioque – the Holy Spirit proceeds from both God the Father, and Jesus the Son. It is interesting to note that this was not an issue in the first 4 centuries of the Church. However, Macedonius in the late 4th century went about teaching that the Holy Spirit is ensued only from the Son.  The issue of the Filioque eventually caused the Greek Orthodox Church to split away in a schism.

The doctrine of the Filioque was declared to be a dogma in the Fourth Lateran Council (1215), the Second council of Lyons (1274), and the Council of Florence (1438-1445). Thus the issue about Holy Spirit was addressed authoritatively by the Church – The Holy Spirit is the Third Person of the Blessed Trinity. While distinct, as a Person, from the Father and the Son, He is consubstantial with Them; being God like Them, He possesses with Them one and the same Divinity. He proceeds, not by way of generation or creation, but by way of spiration, from the Father and the Son together, as from a single principle (Maas, 1909).

This is the evidence from Scripture: In Galatians 4:6, the Holy Spirit is referred to the Spirit of the Son, in Romans 8:9, He is referred to the Spirit of Christ, in Philippians 1:19, the Spirit of Jesus Christ; at the same time, the Holy Spirit is referred to the Spirit of the Father (Matthew 10:20) and the Spirit of God in 1 Corinthians 2:11. Again in places of Scripture as diverse as Luke 24:49, John 15:26; 16:7; 20:22, Acts 2:33, Titus 3:6, the Son sends the Holy Spirit, just as the Father sends the Son (Romans 3:3), and as the Father sends the Advocate, the Holy Spirit (John 14:26). All these means that God the Father, Jesus, the Son, and the Holy Spirit, are the same and One God, while being distinct Persons in One Divine.

We can never know GOD, and all the words in this world cannot contain GOD. Nonetheless, in Baptism, we are extended an invitation to be part of the Community that is the Holy Trinity. As we enter deeper into this mystery, may we be given a tiny glimpse of the wondrous magnificence of GOD.

By the Grace of God,

Brian Bartholomew Tan



Catechism of the Catholic Church. (n.d.)  Libreria Editrice Vaticana.

Cambridge Dictionary. (n.d.), Mystery. In Cambridge Dictionary.

International Catholic University. (n.d.) The One and Triune God – Study Materials. International Catholic University. Retrieved May 27, 2021, from

Maas, A. (1909). Filioque. In The Catholic Encyclopedia. New York: Robert Appleton Company. Retrieved May 27, 2021 from New Advent:

Vanderbilt University. (n.d.) First Council of Nicaea and the Nicene Creed. Vanderbilt University, Retrieved May 27, 2021, from