Tim Keller in a recommended sermon on the Trinity:
If God was unipersonal, there would have been no love until he created the world. However, if the world was created by a triune God, then relationships of love are what life is all about. The Godhead is characterized by mutual self-giving love as the Father, Son, and Holy Spirit orbit around one another in a dance. It is impossible for us to join in if we focus on ourselves, but through Jesus Christ and his sacrificial death on the cross, we can be brought into the dance. Tim Keller
For more on the Trinity, I recommend the brief post Trinity 101 by Justin Taylor
