If the Father, Son, and Holy Spirit had not made themselves personally known, we would not have attained knowledge that the one God is the triune God. A theology that operated without revelation might reason its way to abstract monotheism or to the polytheism of multiple divine agents working in the world, but triunity has to be carefully taught by God. John of Damascus [676-749 A.D.] speaks for the mainstream of Christian thought when he identifies divine self-revelation as the exclusive source of the confession of God’s triunity (Fred Sanders, The Triune God, 37).