LUTHER accepts the orthodox doctrine of the Trinity because he knows that it is supported by the Scripture—not only by the New but also by the Old Testament.1 He emphasizes the “oneness” and the “three-ness” equally.2 God is one and three. His unity exceeds the one-ness of any creature and of any mathematical concept. For this reason Luther has no love for the concept “threefoldness” [Dreifaltigkeit] for “there is most sublime oneness in the deity.”3 But this one-ness is at the same time the three-ness of distinct “persons.” One God in three persons—every person is the entire deity and yet no person exists as the deity for itself without the other two.4 This all is based on the Scripture. Reason admittedly finds all this talk about one-ness and three-ness in God a stumbling block. But since it is based on clear Scripture, reason must be silent at this point and we must believe.5
The concepts used to express this mystery may very well be inadequate. Scripture does not speak of the “Trinity.” But one must teach in this way for the sake of the weak and in order to instruct at all. Whoever wants to use some other expression in place of that of the three persons is free to do it, but he must be very careful to preserve and express the substance which is at stake.6 That substance, however, is these two factors which are both with-
1 “Scripture thus cleverly proves that there are three persons and one God.
For I would believe neither the writings of Augustine nor the teachers of the
church unless the New and the Old Testaments would clearly show this doctrine
of the Trinity.” WA 39II, 305.
2WA 39II, 287 (theses 5ff.).
3WA 46, 436.
4WA 39II. 287.
5WA 10I,I, 152. “Here faith and not all sorts of sharp speculation is
needed.” WA 10I,I, 157, 186. “If natural reason does not comprehend this,
it is proper that faith alone should comprehend it; natural reason produces
heresy and error but faith teaches and holds the truth for it sticks to the Scrip-
ture which does not lie or deceive.” WA 10I,I, 191. Cf. D. 186 of this
volume and WA 37, 44.
6WA 39II. 305, 287.