If it is fundamentalism to argue that names in the Trinitarian formula are important, it is doctrinal suicide to argue that they are dispensible or interchangeable. The Christian Tradition has always understood the Trinitarian
hypostases not as arbitrary names, functions or roles, but rather as true persons in relation (East and West differ a bit here, but the difference does not touch on this matter). Thus the Godhead - in which the Father subsists as begetting the Son, the Son as begotten by the Father, and the Spirit as proceeding from both as the very embodiment of their reciprocal love - becomes the foundation for human interrelations, especially those within the human family (cf. Eph. 3:15). As St. Augustine says of the Spirit, "
And if the love by which the Father loves the Son, and the Son loves the Father, ineffably demonstrates the communion of both, what is more suitable than that He should be specially called love, who is the Spirit common to both?" (
De Trin. 15.27) If, on the other hand, 'Father, Son and Spirit' are no more than dispensible names, then we must be prepared to face the consequence that human love, personhood and relation will become purely human realities, with no basis in the higher, divine realm.