Understanding the Holy Trinity

The Trinity is not an easy concept to approach but its understanding is crucial because it is truly the cornerstone of Christian doctrine. This doctrine aims to represent God united in 3 persons; the Father, the Son (our Lord Jesus Christ) and the Holy Spirit can be difficult to grasp for a beginner and can be the subject of much reading by theology enthusiasts.

In this article dedicated to the Holy Trinity we hope to deepen your knowledge of the latter through 3 distinct modules classified according to your level; beginning, intermediate, advanced. Obviously, there is no shame in being at the beginner level, especially if you started in Christian theology or simply in Christianity, over the course of your life and your experiences this notion and more generally all of the notions specific to the Christian religion will become much more familiar and understanding to you.

Finally, and this is very important to remember, we inform you of the fact that everything that may result from this blog article will be based on the teachings of the Bible and from the point of view of the Holy Catholic and Apostolic Church and the many Doctors of the Church who have addressed this crucial theme in numerous recognized works, notably in this case the works of Saint Thomas Aquinas, Saint Irenaeus of Lyon and Saint Augustine.

Having said that, we can finally begin our article on this fascinating theme of the Holy Trinity.


The Trinity, beginner level (principle)

As previously stated, the Holy Trinity is one of the fundamental notions of Christianity, its understanding is essential to fully embrace the Christian faith and what it represents.

The New Testament then reveals to us that the One God is the union of three persons: the Father, the Son and the Holy Spirit. This is the Trinity. And the principle of the Trinity is present in the Bible in many places.

In Matthew 3.1-17 at the baptism of Jesus (the Son, the Father and the Holy Spirit are also present. Matthew 28.19 tells us that Jesus commands the disciples to evangelize in the name of the three persons of the divinity: “Go, do of all the nations of the disciples, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit." And Paul reaffirms this principle of the Trinity for us in 2 Corinthians 13.13 we find these same three people: "The grace of the Lord Jesus Christ , the love of God (the Father), and the communion of the Holy Spirit be with you all.”

God is therefore the union of the Father, the Son and the Holy Spirit, however be careful if indeed the 3 persons of the Trinity are God they are also and it is obvious individually, thus the Father is God, the Son is God and the Holy Spirit is God but that does not mean that they are 3 different gods, it only forms one is the same God. Finally, we must not also confuse the 3 persons of the Holy Trinity, the Father is not the Son, the Son is not the Holy Spirit who himself is not the Father etc.

To put it simply, the Nicene Creed below explains the Trinity principle perfectly and simply.


The Trinity, intermediate level (more in depth)

Now, it is possible to go into more depth here on the principle of the Trinity, particularly with the principle of divine essence. The Christian Trinity rightly affirms that the 3 persons which compose it, respectively the Father, the Son and the Holy Spirit, are 3 very distinct persons but possessing the same divine essence. This is very often explained with the metaphor of the 3-leaf clover. Each leaf represents a person of the Trinity who all come from the stem which symbolizes the divine essence which is common to them.

God is personal and living, so he is interpersonal in the same way as human beings. To be a complete person, one must turn to another person. Comprehensive communication involves communication with other people. Complete love means loving someone other than yourself. According to the Bible, God is a person and love, which means he is interpersonal, relational, and able to communicate.

In the very nature of God, there is the one who loves and the one who is loved in return. Within the living God, there is an infinite energy of love flowing between the two. The creation of the world and its inhabitants is the visible manifestation of God's loving and relational nature. How God can be one and many remains incomprehensible to our logic, but the Bible teaches that it is possible. The word “Elohim” in the Old Testament, which designates God, is grammatically plural. For example, “the Lord, our Gods, the One Lord” in Deuteronomy 6:4-5.

The Trinity is therefore an obligation so that God can be love, mercy and peace, it must truly be so towards him because if he were only towards his creation then the latter would depend on his creation what would come taint his omnipotence. The Trinity is therefore a true gift from God both for understanding it and for living it.

Holy Trinity

The Trinity, advanced level (theology and metaphysics)

We will begin this module by quoting the very famous and rightly Saint Thomas Aquinas who will rightly affirm that the Holy Trinity cannot be divined by philosophers by themselves, which strengthens the notion of revelation which it makes the object:

Saint Thomas Aquinas : 

“By his natural reason, man can only come to know God from creatures (ex creaturis). Now creatures lead to the knowledge of God like effects to their cause. We can therefore only know of God, through natural reason, what necessarily belongs to him according to his being the principle of all beings; we have asserted this foundation above, in the consideration of God. Now the creative power of God is common to the whole Trinity (virtus autem creativa Dei est communis toti Trinitati); this is why it concerns the unity of essence and not the distinction of persons. By natural reason, we can therefore know about God what concerns the unity of essence, but not what concerns the distinction of persons.

Saint Thomas Aquinas

Saint Augustine : 

On the side of Saint-Augustine, the latter in his commentary on the Gospel of Saint John will affirm that the Holy Spirit does indeed proceed from the Father but also from the Son and that therefore the filioque is a reality. This is essential to correctly appreciate the Holy Trinity because knowing the relationships between the people who compose it is essential: "You ask me: "If the Son is of the substance of the Father and if the Holy Spirit is also of the substance of the Father, why is there not one Son and why is not the other Son?" This is my answer, whether you understand or not. The Son is of the Father and the Holy Spirit is of the Father, but the one is begotten, the other proceeds; therefore the one is the Son of the Father from whom he is begotten, but the other is the Spirit of both since he proceeds of the two. The Son says, speaking of himself: He proceeds from the Father , Jn 15:26, because the Father author of his procession is the one who begot such a Son and who, in begetting him, gave him that the Holy Spirit also proceeds from him. For if he did not also proceed from him, he would not say to the disciples: Receive the Holy Spirit (Jn 20:22) and he would not give it to them by breathing so that , meaning that it also proceeds from him, he ostensibly shows by blowing what he secretly gave by his inhalation.

Since then, if he were born, he would be born not only of the Father, nor only of the Son, but obviously of both, he would undoubtedly be called the Son of both. And therefore, since he is in no way the Son of the two, it was not necessary for him to be born of the two. He is therefore the Spirit of both, proceeding from both.

But who, speaking of this sovereign nature, can explain the difference between being born and proceeding? Not everything that proceeds is born although not everything that is born proceeds, just as not everything that has two feet is a man although every man has two feet. This I know; to distinguish between this generation and this procession, I do not know, I cannot, I am not capable of it. And since both are ineffable, as the prophet said of the Son: Who will tell of his generation (Is 53:8)?, it is said in all truth of the Holy Spirit: Who will tell of his procession? Let it be sufficient for us to know that the Son is not of himself, but of him from whom he is born, that the Holy Spirit is not of himself, but of him from whom he proceeds, and that he proceeds from both, according as he is called the Spirit of the Father and the Spirit of the Son (Rom 8, 11 and 9)" ( Contra Maxim. , 2, 14, 1)

Saint Augustin

Saint Irenaeus of Lyon:

Finally, Saint Irenaeus of Lyon will at the same time combat the heresy that the God of the Old Testament is not the same God as that of the New Testament which is an unnamed heresy but will also try to define the Holy Trinity who reproached many for trying to understand God with their little human knowledge:

First deviation: the Marcionite thesis of the two Gods, the "just" and inhuman God of the Old Testament, and the "other" God, the "good" God revealed by Christ in the New.

The Gnostics follow in Marcion's footsteps: they imagine above the God creator of all things called "Demiurge" a divine "Pleroma" composed of thirty aeons, or entities emitted from the first and superior to the Demiurge. This would have its origins in an evil passion arising in the Pleroma, and would be "the fruit of a decline" (cf. AH II,1,1)

Irenaeus' profession of faith falls along the lines of a refusal and a choice: refusal of a God foreign to history; choice of a God present in history, through his Logos always present to the human race, Logos who became humanized "when the times were fulfilled":

Irenaeus not only recognizes God in the Creator but identifies him with the Father:

God is the Father of a Son who is eternal , and the Father of men who, having had a beginning, "become" sons by means of "economies" (cf. AH II,25,3; III,18,1 ; V,36.3).

Therefore, the name of God is suitable for no one but the Father, and yet God is also the name of the Son, and becomes so for sons by adoption:

“It is an assured and indisputable thing that no one has been proclaimed God and Lord absolutely by the Spirit except the God who rules over all things with his Logos and those who receive the Spirit by adoptive sonship , that is to say of those who believe in the one true God and in Christ Jesus, Son of God" (AH IV,1,1).

Saint Irenaeus of Lyon therefore affirms in his works that Christ is indeed God and reigns at the side of the Father and in communion with the Holy Spirit.

Irenaeus of Lyon

The Trinity, conclusion

The Holy Trinity is therefore a difficult notion to fully understand, even for the great Doctors of the Church who for decades have questioned this crucial notion of Christian theology. However, the main thing can be summarized in a few words:

The Holy Trinity is made up of the 3 divine persons, the Father, the Son and the Holy Spirit who are all 3 God but are only one unique God and who are not confused through their persons even if the latter share the same divine essence.

Understanding the Trinity is understanding Christian dogma, so in parallel with this article we advise you to do your own personal research via verified sources Aleteia.Org or Finally, do not hesitate to question a man of the Church and in particular the priest of your parish on this subject, be blessed and remember that "nothing is impossible" with God Luke 1: 37 .

Holy Trinity
If you want to know more about how to convert to Christianity, our blog article dedicated to the latter entitled “How to convert to Christianity” should really appeal to you.