There is only one God, but there are somehow 3 distinct, divine persons: Father, Son, and Holy Spirit. Since each of these persons are 100% God, we can’t say that there are 3 parts to one God. Instead, we know that each of them are equal and eternal, yet somehow truly distinct. While this is beyond our human capacity for understanding, what we can grasp is that God is an eternal, active relationship of love - each person giving themselves totally to one another. If we are made in the image and likeness of God, then we, too, are called to give ourselves totally to others. Only in a freely given, authentic act of love do we discover the true meaning of what it means to be human.