Al-Ansari—and others besides those two—report that the Christians say: “The Eternal One is single in essence yet triune in hypostasis,” and that by “hypostasis” they mean existence, life, and knowledge.

They also transmit from them that life and knowledge are not two additional, externally existing attributes over and above the Essence; rather, they are intrinsic attributes of the very substance.

They add: “If one wished to illustrate their doctrine with an example, one could say that the hypostases, in their scheme, correspond to the ‘states’ and intrinsic attributes affirmed by certain Muslim theologians; for the blackness of a color and the fact of being colored are both intrinsic attributes of an accident.”

He continues: “They may at times express the hypostases as the Father and the Holy Spirit, intending by ‘the Father’ existence, and by ‘the Son’ the Messiah—the Word—and they may sometimes designate knowledge…"