(11) Is the Trinity Biblical? (BC 9)

The Athanasian Creed summarizes the Christian faith in this way, "We worship one God in Trinity, and Trinity in Unity." Orthodox Christians affirm that there is only "one simple and spiritual Being" (BC art. 1) who exists in three distinct, though undivided persons, the Father, the Son, and the Holy Spirit. All three persons are coeternal and coequal (Ath. Creed art. 26).
The church's position on the trinity, to modern ears, is shockingly rigid. The Athanasian Creed says, "He therefore that will be saved must thus think of the Trinity" (art. 28). Is it right for us to so inflexible in our understanding of God? How can we be so sure that this is the right way to think about God?
The confession explains that we know God as Triune from the testimonies of Scripture, from the church, and from personal experience. What Scripture and the church tell us is true must lead to the worship of the triune God.