The doctrine of the Trinity is a revealed mystery. It is in some ways less revealed than other doctrines, and in other ways more revealed. It is less revealed in this sense: it is not directly proposed in the words of Scripture and presented to us in a formulated state. Some doctrines are. . . . But the triunity of God is not made known in that way. It is not set forth in oracular idiom in the Old Testament (“Thus saith the Lord: I am Father and Son and Spirit”), nor is it made the subject of focused and deliberate teaching in the New Testament (“Now concerning the persons of God, I would not have you ignorant . . .”). The basic vocabulary of Trinitarian theology is not found on the surface of the text (person, nature, relation, threeness), and the conceptual elements of Trinitarianism are not gathered in one place and related to each other by Scripture itself. We nevertheless call it a revealed doctrine, and even a biblical doctrine, because, as the Westminster Confession of Faith reads, “the whole counsel of God . . . is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture.” The triunity of God is among those things “by good and necessary consequence deduced” from what is “expressly set down.” To call it less revealed than other doctrines is simply to admit, with calm confidence and equanimity, that it is not verbally formulated for us, and that some assembly is required (Fred Sanders, The Triune God, 39-40).