How We Know That God is Three-in-One

The revelation that God is Trinity, Three Infinite Persons subsisting in the unity of One Infinite Mind and Will, is the great Theory of Everything that makes sense of everything in our experience of the world. In this book we will see how it is the Trinity that explains the undeniable but unfathomable facts of everyday life encountered by the human race: 

The phenomenon of knowing, our capacity for understanding

The power of willing, of choosing, loving and giving of ourselves

Our existence as selfs/persons that know, love and find fulfillment in relationship

The emergence of a new person, a new "I" from the loving union of two other "I"s 

The creativity, rationality, and energy that constitute the world 

The belief of three "centers" within God found in the greatest pre-Christian religious traditions which represent the three main human approaches to God: cyclic-mystical (India); unity-in-multiplicity/harmony (China); historical-linear (Israel). 

Jesus' revelation of the Father, of his own Sonship and of the Spirit of the Father and the Son 

We know because God is Knowing, we love because Loving is the Life of God, we are selfs/persons with minds and wills who commune and reproduce because the infinite Mind and Will is a communion of interacting Selfs/Persons. 

The Trinity is the Big Picture that connects all the disjointed dots of our experience of the world and ourselves. At the center of being, we now know, there is meaning and communion, knowing and loving, agent-hood and activity. And the entire dynamic of the universe is driven by the endless creativity, rationality and energy of the Triune Life.

Since God is infinite love, there has to be love within God. Since God is infinite, this loving, its object and its fruit must likewise be infinite: Three inseparable "centers" that ARE the One. And in what would such love consist? In a giving, receiving and sharing in full of the divine nature, of all that it means to be God. A child receives its human nature with all its powers from its parents as a manifestation and fruit of their love. Likewise, the love within God is a giving, receiving and sharing in full of the divine nature with all its infinite power and glory.  

It is a love without beginning or end, a LOVE that IS. "Trinity" is not God's proper name. It is simply a way of saying that God is infinite love. To say that God is Trinity is simply to say that God is LOVE.