Necessity of a Triune God


I was asked this question by a person who believes in a single “Godhead” and I’m not really sure how to respond:

“If you believe that the Saviour of Mankind always existed with God the Father in Heaven, did God know that ‘man would fall?’ If God didn’t know, then why would there be Jesus? Dosen’t this indicate that Jesus came to be after creation and the fall of man? What would be Jesus’ role if man didn’t fall?”

I told him that the Bible was very explicit in saying that Jesus was not “made up” just before the Virgin Birth. I don’t really know how to answer the question though. It got me thinking. Would a Triune God indicate a pre-planned role for all three persons of the Trinity? I’m just really confused now. Usually when I’m doing my amature apologetics, I’m never really shaken and I almost always have a decent answer, But this question really stumps me. Please help!


Dear Joseph,

Jesus existed with the Father and the Holy Spirit from all eternity. God knows all things and certainly knew that Adam would fall. St. John the Evangelist calls Jesus the Word of God. The Prologue of the Gospel of John reads: “In the beginning (of the world) was the Word: the Word was with God and the Word was God. He was with God in the beginning. Through Him all things came to be, not one thing had its being but through Him. All that came to be had life in Him and that life was the light of men, a light that shines in the dark, a light that darkness could not overpower.” (Jn 1:1-5) “The Word was made flesh, He lived among us, and we saw His glory, the glory that is His as the only Son of the Father, full of grace and truth.” (Jn 1:14)

The Gospel says explicitly that the Word was God—not even that He became God. Of course, He couldn’t become God because God cannot change or be lacking in any way. If Jesus is God, then He has always been God. And hear this: Jesus doesn’t have to justify His existence by our need for a savior. The Trinity was quite complete and happy without us. But love is diffusive of itself and so God chose to create the human race for the benefit of the race—not for the benefit of God.

If you will note, that it was through Jesus that the Father created all that is. Not one thing came into being without Him.

Fr. Vincent Serpa, O.P.

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