Yesterday the Catholic Church celebrated the Feast of the Holy Trinity: the mystery of one God in three persons. It is definitely a mystery we will not ever completely understand in this world. However, the best explanation that has brought me to a much clearer understanding of the Holy Trinity stems from the teaching of Blessed Pope John Paul II's Theology of the Body (TOB). This is what I love about Theology of the Body: not only does it teach us the whys behind the Catholic Church's moral teachings on sexuality, it points toward an explanation of the sacraments and some of the basic foundations of Her teachings about God.
So, one God three persons... What do we know about God? God is love. Ok, so if God is love, can one just love oneself? One can, but that becomes pretty narcissistic. Imagine God sitting around loving himself. Ludicrous. That is not God's nature at all.
John 3:16 For God so loved the world that he gave his only Son...
Love stories that move us are typically at least between two people, right? What is it that is moving about a love story? The exchange of love between two persons. The very nature of love itself is that it has to be given, poured out. And in true, pure love it is received and then given back, poured back out.
So, the first two persons in the Holy Trinity: God, the Father, gives of himself, pouring his love into the Son, who receives God's love. The Son, in turn, gives of himself, pouring his love into the Father, who receives the Son's love. For those of us blessed to have wonderful relationships with another, be it a friendship, parental relationship, spousal relationship, etc. we can well understand this two person exchange of love.
Ok, so then why three persons? Herein lies another truth about the very nature of love: love by its nature is fruitful, life-giving. The love between God the Father and God the Son is so perfect, so true and pure that it is out poured into another being completely - the Holy Spirit. Their love is so beautiful, so awesome that it cannot be contained and the love that is "produced" between the two persons has its own person hood - the Holy Spirit.
Ok, so our understanding of time and space makes this last part a little bit tricky. God existed in totality before time and space came into being. Meaning, God the Father, Son AND Holy Spirit all existed together from the very beginning. I think this is where the mystery part comes in - our understanding of time and place makes this confusing for our minds.
But if God is love, this explanation does make sense. And in Theology of the Body (TOB), since we are made in God's image, read we are made in the image of love, the marriage between a man and a woman mirrors the Holy Trinity. The man pours his love out and it is received by the woman, who in turn pours our her love and is received by the man. This unity of their love, God willing, produces a whole new being - a little human person. Pretty awesome this plan God has for us. His plan, his creation of us as male and female, is perfect. It actually can reveal for us a bit about the nature of God himself. Absolutely beautiful!