At the end of a long and interesting article examining hints of the triunity of God in the creation narrative of Genesis 1, Peter Leithart concludes:
The Bible never teaches a merely-mono theism, not even for a single verse. As soon as God is named, we have a hint of plurality within the life of the Creator. As we read the account of creation, that whisper becomes more audible. And those hints of divine plurality provide the only coherent ground for the biblical teaching concerning creation. In fact, the Father, Son, and Spirit created all things. But it’s also the case that only the Triune God can create.
Creation is an act of sovereign independence. A Demiurge can shape pre-existing material, as much as the material permits. Shaping is not creating. A Creator must not be dependent on pre-existing material, hemmed in by its limits and resistances. And a Creator must be capable of making and doing as He wills. No monadic, unitarian God can be sovereign and independent in the way a Creator must be.
Think, first, of the life of a unitarian God without creation, then with creation. Absent creation, this God is utterly alone. Since there is no other, there is no communion or love. It doesn’t matter if the unitarian God possesses infinite potential for mercy, kindness, and love, for un-enacted love is not love. Further, absent creation, a unitarian God is unproductive, barren. He does not, by nature, beget or breathe out. He is unfruitful and uncreative in himself. Once this unitarian God forms a world outside, everything changes. Now he encounters an other. Now his infinite potential for communion begins to be realized in action. Now he is fruitful, and his light has radiance. Notice what has happened: The unitarian god can only realize the fullness of his divine life if he makes the world, and so he is dependent on the world for his full realization. He hasn’t created, because he has not acted with sovereign independence.
It’s not even clear that such a God can make anything outside himself. If there is no active productivity within the life of God, then by what mechanism does he become productive? This is not merely a question of mutability – the change from an unfruitful to a fruitful being. It is a matter of possibility: If the God is not productive in himself, he requires something other than himself to become productive. He cannot be Creator God, because his Creator-Godness, his capacity for producing a world, is dependent on an external catalyst.
Now, consider the life of the Triune God without, then with creation. The Triune God is an eternal communion of Persons, living eternally with other and other, relation and relationship among the Persons. This God’s love isn’t merely potential love; His love is eternally actualized in the Father’s love for the Son that is the Spirit. None of His attributes are merely potential, because He eternally enacts and realizes His justice, truth, faithfulness, jealous love, holiness in the communion of three Persons. He needs nothing other than himself to realize himself. Besides, the Triune God is fruitful within Himself. The Father, Athanasius says, has a “generative nature,” eternally producing the Other who is the Son through the other Other who is the Spirit. He is root and fruit, source, radiance, and diffusion. Since He is naturally and eternally productive, He can be a source for creation. Productivity is not alien to His life, not a potentiality realized in the production of the creation. Love for an Other is inherent in the life of God, and so it is natural for God to love a creation that is not God.
The choice is between a God who remains sovereign and independent only by remaining alone and barren, only by having no realm to rule; or, the living Triune God. And that choice is posed to us at the outset of the Bible, in the proto-Trinitarian creation account of Genesis 1.