Is each person of Trinity necessary?


I was wondering if there is any argument showing that each person of Trinity is necessary.


It’s necessary because of God’s very nature.

Because God is Knowledge, he necessarily has to have a Word.

Because God is Love, there necessarily has to be a Holy Spirit.

That’s the two-line gist of it.


What do you mean by that? If you mean necessary in the philosophical sense, then it’s very simple.

The Father is God.
The Son is God.
The Holy Spirit is God.

God is totally necessary, that is, not contingent.

Therefore, each person of the Trinity, since each is fully God, is necessary.




One can increase or decrease this list.

I can buy this for sake of argument.

This doesn’t follow. My question specifically is that why number 3 and not any other number.


I can agree on these, but if His word is Son then Son cannot be God. The same for love. Moreover it is very strange for me to assign the attributes of God as person. How about His ability to act, omnipotence. Why that is not a person?


Yes, very necessary. To deny any part of the Trinity is to deny God himself.


All such argument is academic, if not strictly sophomoric. The Trinity has been revealed to mankind by an inscrutable God.

Perhaps a poor analogy, but might as well ask if we truly need oxygen, or whether we could survive on some substitute.


And because God is the Creator, His other nature is Father


Nope. The Word must also necessarily be God.

Because God is Knowledge, even “before” anything was (and I am forced to use scare quotes because God is outside of time), he necessarily needed an object for that Knowledge, and “before” anything else was, the only object of that Knowledge is himself. By knowing of himself, he conceives an Idea of himself. We do the same: we are objects of our own knowledge, that is to say, we know ourselves and conceive ideas of ourselves, and these ideas of ourselves are in a manner of speaking, images of ourselves. But because of our inherent limitations, we are unable to form a complete, full idea of ourselves. The idea we conceive of ourselves is not quite ourselves, and even then we don’t know ourselves in full as we ought. Any idea we have for ourselves is inadequate.

This cannot be so with God. The Idea he forms of himself is not inadequate: it cannot be because there is no inadequacy in God. Therefore, by his very nature of being Knowledge, he must necessarily have the first Idea, which is only of himself as the first object of his knowledge, and that Idea can only be perfect and infinite, because there is no inadequacy in God. There is only one Perfect and Infinite: and that is God. The Word (Logos, Idea) is necessarily perfect and infinite, and therefore must necessarily be God.

Because God is Love, the Father and the Word must also love each other with a love worthy of God. However, the divine Love cannot be finite, otherwise, we are introducing a limitation into the very nature of God. It is therefore impossible for that love to be anything less than infinite and perfect, and there is only one Infinite and Perfect: that is God himself. That Love must also therefore be infinite and perfect, and therefore God himself.

But since the Father is distinct from his Idea of himself, the Word cannot be the Father, as the Father is unbegotten and the Son begotten. And as the Spirit proceeds from the divine Love between Father and Son, the Spirit necessarily cannot be the Father nor the Son. Hence, the Athanasian Creed and the Trinitarian Shield.

As for the attributes of God, we do not equate them as a Person. God’s attributes are equivalent to his essence, not to a person. So when we say God is Knowledge, we do not attribute that Knowledge to the Son. That Knowledge is equivalent to the Divine Nature, inherent to the three Persons. What the Son is is the Idea that God conceives of himself from eternity, an idea so perfect and adequate such that coming from the divine Mind, it cannot be anything but perfect and infinite, the very definition of God.


What do you mean by necessary in this case?


Because God is not contingent, there can be no explanation. Analogies might help, but they do not justify. There are three persons of God, so there are 3 persons. It is necessary because it is.

Try this. When I speak, my breath gives voice to a word that means something to somebody. Hopefully. Not always lol. When God speaks, the Holy Spirit fills the Word and makes it present. Does the Speaker speak if there is no Word? Is the Word present if it is unspoken, or cannot be heard? Does any of that matter if there is no Spirit to carry the word to us and let us hear? Are all 3 necessary for God to speak?



God is not Father because he is Creator. He is always Father from Eternity because he eternally begets the Word.


We have the number three from divine revelation. It’s not strictly speaking something that can be determined through natural philosophy alone. There have been philosophical reflections on this, why the processions of the Son and the Holy Spirit differ, and why there cannot be additional processions, but those are after-the-fact of revelation.

But consider that we are not talking about three beings and adding more or less beings. We are not talking even about three persons in the sense of what we mean by a human person (or what we would think of as an angelic person, or a non-human alien person). We’re simply referring to some sort of distinct relationship within God, not real additional beings. In God there is a generation from his knowledge. If there were any other generations from his knowledge, those would be identical, and so no different. In God there is a procession from his will, a spiration but not a generation, and any other spirations in this fashion would be identical relationships and therefore not distinct relationships.

There can only be one generation, for any additional generations would be exactly identical and could not be distinguished from each other. There can only be one spiration, for any additional spirations would be exactly identical and could not be distinguished from each other.


Man mirrors the Trinity. We were created in His image:


Body = Christ
Soul = Holy Spirit
Mind = God

Any other number wouldn’t make sense. We would be completely different in our structure if there was not a Trinity but something else.


So your question is why does it have to be three?

The answer is necessarily a theological one, since this concerns revealed truth not otherwise accessible to the human intellect. Will you accept a theological answer? If not, the discussion really can’t go any further.



This is the heresy commonly known as “partialism” and denies the de fide dogma that God is absolutely simple.

Do not use analogies when trying to explain the Trinity. It will result in some kind of ancient heresy and for the uninitiated, will distort his understanding of God.


Well 1. Never heard of partialism before.

  1. I don’t believe God is absolutely simple? So I guess I’m a heretic.

  2. I’m sorry but we are made in His image and to me this is how it manifests. Are we NOT one even while being three parts??? Because I dunno about you but despite having a mind, soul and body I feel like one person. I do not believe that each part is separate and not part of me, in the same way I do not believe the Trinity are separate from God but are all God.


…taught that Father, Son and Holy Spirit together are components of the one God. This led them to believe that each of the persons of the Trinity is only part God, only becoming fully God when they come together.

(I don’t think this was your intent—or what you meant)


Yeah, that’s not at all what I said or what my analogy insinuated but if you got that from it then okay.


Yes, God is not the object of knowledge, The Word. That is Son. Therefore Son cannot be God since He is only object of knowledge. He is not Love for example.

By the way, why you don’t assign an person to God’s ability to create, omnipotence?

Again, Holy Spirit cannot be God since He is only object of Love.

I can agree on this if Son and Holy Spirit are not God.

Why call The Idea that God has about himself as a person and then God?

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