Faithful instruction of the next generation is the normal mechanism God employs for the advance and growth of his people (Donald Van Dyken, Rediscovering Catechism: The Art of Equipping Covenant Children, 7).

The way to be patristic is to learn to discern the doctrine of the Trinity in Scripture, as the fathers did, and not to blame the doctrine on churchly creativity, as their opponents did (Fred Sanders, The Triune God, 81).

Before the persecution of my day, the message given through Christ to the world of reverence to God was accorded honor and freedom by all men, Greeks and non-Greeks alike. Rulers granted our people favors and even permitted them to govern provinces, while freeing them from the agonizing issue of [pagan] sacrifice. In the imperial palaces, emperors allowed members of their own households–wives, children, and servants–to practice the faith openly, according men like the loyal Dorotheus and the celebrated Gorgonius higher favor than their fellow servants or even officers. All governors honored the church leaders, mass meetings gathered in every city, and congregations worshiped in new, spacious churches that replaced the old. This all progressed day by day, the divine hand protecting its people from jealousy or plot so long as they were worthy.

But greater freedom brought with it arrogance and sloth. We began envying and attacking one another, making war on ourselves with weapons formed from words. Church leaders attacked church leaders and laymen formed factions against laymen, while unspeakable hypocrisy and pretense reached their evil limit. Finally, while the assemblies were still crowded, divine judgment, with its accustomed mercy, gradually started to intervene, and the persecution began with our brothers in the army. In our blindness, however, we made no effort to propitiate the Deity but, like atheists, assumed that our affairs went unnoticed, and we went from one wickedness to another. Those who were supposed to be pastors, unrestrained by the fear of God, quarreled jealousy, and hate, frantically claiming the tyrannical power they craved. Then it was that the Lord in his anger humiliated his daughter Zion, in the words of Jeremiah, and threw down from heaven the glory of Israel [Lam. 2:1-2]. And, as foretold in the Psalms, he renounced the covenant with his servant and profaned to the ground his sanctuary–through the destruction of churches–exalting the right hand of his servant’s enemies, not assisting him in battle, and covering him with shame (Eusebius, The Church History, Translated by Paul L. Maier, 85).

“When Christian families imitate Christ, then a skeptical world is confronted by the beauty of our God” (William Gouge, Building a Godly Home, eds. Scott Brown and Joel R. Beeke, I:ix).

In short, any appeal to the rule of faith and its use by the church fathers must make it clear that tradition is the medium, but not the source, of the doctrine of the Trinity (Fred Sanders, The Triune God, 85).

The Trinity is a revealed mystery in the biblical sense of the word mystery. And it is not enough to list it alongside other mysteries, because it concerns the entire scope of salvation history and makes known the actual identity of God. As a doctrine covering territory so deep and wide, it is a mystery without peers; it is the one primordial mystery of God’s being and works. The triunity of God has always been, was once concealed, and is now revealed. The manner of its revelation should establish the order and structure of the doctrine concerning it, as well as the order and structure of adjacent doctrines like revelation and salvation (Fred Sanders, The Triune God, 68).

We will be arguing throughout this book that the Trinity is a biblical doctrine. But it is not enough to say that the mystery of the Trinity is in the Bible unless we recognize that the thing we are calling the Bible is a set of texts that were written, redacted, and canonized to prepare for and report on the missions of the Son and the Spirit. To somebody about to come through the texts to find the elements of the doctrine, we have to say: the Trinity is in the Bible because the Bible is in the Trinity (Fred Sanders, The Triune God, 44).

A doctrine of revelation uninformed by Trinitarian realities could not be the proper setting for the doctrine of the Trinity (Fred Sanders, The Triune God, 42).

But the doctrine is also, in another and higher sense, more revealed than most doctrines. The root idea of revelation is not verbal announcement but the unveiling or disclosing of something that has been present, though concealed. In order to inform us that the Father has a Son and a Holy Spirit, the Father sent the Son and the Holy Spirit in person. The triunity of God was revealed when the persons of the Trinity became present among us in a new way, showing up in person and becoming the object of our human observation. The apostles testified that what they saw with their eyes and touched with their hands was “that which was from the beginning,” because it “was with the Father and was made manifest” to them (1 John 1:1-3). Doctrines that are first announced verbally have a character of revealedness less directly; the doctrine of the Trinity has it more directly. There are profound reasons that the doctrine of the Trinity has this special status, but at this point it is sufficient to note that this is in indicator that the doctrine of the Trinity is more than just another doctrine on the list of true things we have been taught by God about God. It is God’s self-revelation by way of presence in a more direct, intense, and personal way (Fred Sanders, The Triune God, 40).

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).