Some Basic Trinitarian Thought: The Trinity as Eternal Triune Communion of Love

2. The Father, Son, and Holy Spirit are, according to the Early Church three persons, who share one Being.  The Son is one in Being with the Father, and the Holy Spirit similarly is one in Being with both the Father and the Son.

3.  The result?  A perfect diversity in unity, unity in diversity: a true communion.  The diversity does not make impossible the unity of their Being; nor does the unity obliterate the diversity of the Persons.

4. How is this possible?  Because this unity is a unity of perfect love. This unity of perfect love necessarily involves a "three-ness."  First, an original source of love -- a "person" -- who bestows Himself infinitely (that is to say, fully and completely), namely the person called the "Father";  second, a person who receives that love fully and completely and gives itself back in love infinitely (that is to say fully and completely), namely the person called the "Son"; and also an infinite love that binds them together infinitely (that is to say fully and completely), namely the person called the "Spirit".

5. Thus we say that there are three "persons," one "Being."  The person loving is God Himself (fully and completely God); the person being loved and loving in return is God Himself (fully and completely God); and the love being shared between them is also God Himself (fully and completely God).  Note, moreover, that since God is the source of all love, as He is the source of all existence, the love that binds together the Father and the Son cannot be anything other than God, but it also cannot be the same Person as either the Father or the Son.

6. There are truly three Persons, not one:  the person loving is not the same person as the person being loved and loving in return; nor is the love shared between them the same as either person.  They are truly distinct and "other" from each other.

7. And yet, although there are truly three Persons, there is only one God (one eternal Being).  The Son is "one in Being" with the Father, as is the Holy Spirit.  There are different Persons – three of them – but one God, one eternal Being.

8. What is the difference, then, between "Being" and "person" (in the definition "three persons, one Being")?

9. Well, we can understand one of the words -- namely, one "Being" -- if we remember that God is the Source of All Being;  that is to say, He is Subsisting Being Itself.  Whatever there is that exists in the universe only exists because it partakes of existence from this Source.  We "have" some existence;  we "partake" of existence;  we are not "existence itself" (the source of all existence).  "God, "the Creator," on the other hand, does not "have" some existence;  He does not "partake" of existence from some other source.  No, He "has" His own existence;  indeed, He "is" His own existence.  He is Existence (with a capital "E").  He is Subsisting Being Itself.  Thus, in God, there are not three "Beings."  If so, one "Being" (the source of all Being) would have had to "create" the other two out of nothing.  Rather, there is but one eternally existing God who is Being Itself.

10. So God is one Being.  What, then, is a "person"?  One answer:  a "person" is an individual substance of a rational nature.  What does that mean?

11.  Consider:  a cactus is a being (a created being);  a lead paper weight is a being;  Aunt Sally is a being. Which of these is a person?  Only one: Aunt Sally.  Aunt Sally is an "individual substance" (just like the individual cactus and the individual paper weight), but she is a different kind of "individual substance":  unlike them, she has a "rational nature."

12. Aunt Sally is the kind of being which is also a person.  Uncle Bill is another being, just as the cactus and the paper weight are other beings, but Uncle Bill is also a person.  So although Aunt Sally and Uncle Bill are both persons, they do not, however, share the same act of existing, do they?  They are not the same Being.  (They are also not the source of their own existence, let alone the source of the existence of everything in the world.)

13. What do we have to think about "persons" in God at all?  For two reasons.  One, because we have in the Scriptures many references to "the Father, Son, and Spirit."  And because, as C. S. Lewis pointed out to us, if we say that God is love (if, for example, God has revealed Himself as not only the Source of all Being, but also as Love Itself), then it must be the case that God contains multiple "persons":  the Lover, the Beloved, and the Love which They share.  But all three of these "persons" must be fully and completely God.

14. Thus Christian revelation demands that we say that in the Source of All Existence, namely that which is Subsisting Being Itself, there are three "Persons" sharing the same act of Being. Each Person -- and indeed all three Persons -- are fully and completely (not partially) Subsisting Being Itself. But again, remember that the Person who is the original source of infinite love is not the same Person as the Person who receives and gives itself back love infinitely, nor is either of those two the same as the love that binds them together infinitely. 

15. This is difficult to imagine.  Why?

16. Well, because of our own limitations, both intellectual and spiritual. When we concentrate on the diversity, we lose hold of the unity (because for us, "different" means "separate": one person is one being, two persons are two beings, etc.).  When we concentrate on the unity, we lose hold of the diversity (because for us, so often in bad relationships, when we "give" ourselves to others, we lose ourselves).  But in God, both are true at the same time: perfect unity and diversity of persons, with the personhood (the personality?) of no one of them "overwhelming" or "obliterating" or "diminishing" the personhood of any of the others.

17. Christians believe that God created the universe (including us) out of love.  He loves us infinitely.  But in the case of the universe, we can say that there "was a time when it was not."  But of the Son and the Holy Spirit, we cannot say that "there was a time when they were not."  They have always been sharing this eternal communion of love with each other – this complete unity-in-diversity.  This loving, being loved, and the loving, have always been existing, even before the universe existed.  Indeed, this eternal communion of love transcends time and space (something which is sometimes true – something which we experience in part – even in our much more partial loving).

18. According to the Second Vatican Council, we can "share in the divine nature": we can participate in this eternal communion of love which has been going all from all eternity – even before the world was created.  Indeed, the world was created because of the fullness and fecundity of that love. It didn't "need" others, but it was a joy and a delight to share the love with others.

19. Isn't the same thing true of good parents?  The child is the fruit – the incarnation, as it were – of their love.  They don't "need" the child to make their love full and complete.  It isn't the case that the existence of the child produces their love for each other (although, at times, that can happen too). Rather, they love, and their love produces the child.

20. So, on this view, our salvation involves sharing in this divine threefold communion of love between the Father, Son, and Holy Spirit which has been going on from all eternity.   Sin, as we shall see, is what keeps us from sharing fully in that loving communion, and that is the real tragedy of sin.  Thus, while the doctrine of our redemption from sin is very important, we need to understand it as a means to another end:  namely, an eternal communion (unity in diversity and diversity in unity) with the God who is love.