Trinity Sunday in 2025 comes during the 1700th anniversary year of the Council of Nicaea (325), a crucial point for the definition or confession of God as Trinity. Recited by most readers each Sunday, the Creed proposed in 325 at Nicaea (and revised in 381) does not contain the word “Trinity,” but asserts the unity (“of one being”) of Father and Son that amounts to trinitarian belief, as well as (in less detail, because it was less immediately controversial) the co-equal status of the Holy Spirit.
The word “Trinity” of course does not occur in scripture; it is the witness to God’s reality in the New Testament that makes this doctrine the compelling result of reflection on those scriptures. No single work is more important to that process than the Gospel of John, in which the unity of the Father and the Son, and the work of the Spirit as the presence of the Son and the Father, is asserted again and again.
This pithy excerpt from John 16 exemplifies this implicit Johannine trinitarianism. We hear in this Gospel for one last time from the extended farewell discourses that have appeared through the recent Easter season (this means, by the way, we have gone from John 13 to 14, to 17, back to 14, to 16…). This passage assumes what we had read in chapter 14 in particular, that the absence of Jesus is a necessary condition for the presence of the Spirit of truth (Paraclete).
Now the distinctive emphasis is on the truth that will be revealed by the Spirit; so there is a connection with what we think of as “doctrine” here. Jesus however says not just that there is more to be revealed, but that the disciples actually cannot receive more now. This is a hint at what we are dealing with in understanding the Trinity, or (in John’s terms) understanding or receiving what the Spirit will teach us of what is true of the Son and the Father. The difficulty is not just about stages of the curriculum or an intellectual challenge, but about something that will have to change in the disciples themselves in order for this truth to be received.
This way this inability (v. 12) to receive is couched—”you cannot bear them now”— would in modern English usually imply struggle or pain. They certainly don’t have the capacity to receive what the Spirit will give; it would be incomprehensible to them. Yet the things that the Spirit would say might also be too hard to take (on which more below). So they will receive not just more information, but a changed situation in which the content and form of the Spirit’s truth becomes conceivable.
“All the truth” (v. 13) however seems like a lot under any circumstances. The Greek text varies somewhat here, but the best manuscripts actually say something like “into things that are all true” or (Barrett) “guidance in the whole sphere of truth.” So the disciples will inhabit the truth, and it will be their way of life, not their possession. Truth in John does not simply mean accuracy or facts, but consistency with the nature of God, which means it has character and content. Truth is not mere information, but also a form of practice, a way of being. This is what the Spirit will bring.
The Spirit will “declare to you the things that are to come.” This reference to the future has a dual sense, an ambiguity that is so often important in John. After the readings of recent weeks that seemed to take the disciples and the reader out of the immediate scene (i.e., the Last Supper) into a future well beyond, even to the horizon of eternity, we might assume this distant future is the sole meaning there too. Yet the “things that are to come” also means more straightforwardly “what is about to take place.”
It would not be enough—in fact it would be quite misleading—to think this is a vague promise of revelation as a future property or gift, or even just an assurance of guidance from the Spirit. The path of Christian history is littered with well-intentioned versions of this interpretation, with failed claims to certainty and inspiration collapsing as events took their course. This sort of failure is related closely to the last point; the promise of the Spirit isn’t about knowing everything, it’s about being given what we need to know, and being given knowledge that has a particular character. We should read the passage as, at least initially, something like “the Spirit will make sense for you of what is about to happen, and which otherwise would be completely baffling and impossible to accept.”
So the promise about knowledge of things to come is initially about the events of the next few days, and what they reveal, shockingly, about the nature of reality and of God. For the kind of knowledge, and the kind of life, and the kind of information being promised, can only be understood and accepted if it is grounded in the events of Jesus’ self-giving. This should become even more obvious to those who have been following these Eastertide readings from John when Jesus goes on to say “He will glorify me, because he will take what is mine and declare it to you” (v. 14). “Glory” in John is always centered on the Cross; so the gift of the Spirit is necessarily bound up with understanding what is to happen there. That we have to understand, and then (and only then) knowledge of other things, a different future we can inhabit in the light of this glory, can be borne.
Another version of the promise of knowledge—and more— comes at the end of the passage. The NRSV has “he will take what is mine and declare it to you” (v. 15). A more accurate (if inelegant) translation would be “he will take from what is mine (or “from among the things that are mine” and declare [those things] to you.” This confirms what we already noted; the promise isn’t omniscience, it’s confidence in the nature of what is given.
“What is true,” and what will be given and received, has to be understood relative to John’s picture of the coming relationship between the disciples, the promised Spirit, the Son, and the Father. The promise of truth and guidance is not an intellectual commodity or a body of knowledge such as a doctrine, but a relationship. The effect of the gift is not just growth in knowledge, or even closeness or gratitude, but incorporation into the set of relationships he has been describing. The really difficult thing about the Trinity then may be less the doctrinal complexity as the relational demand, which is of course also a promise, and which then leads us to articulate the doctrine.
Jesus promises—we can say, from our vantage point outside the immediate story—the disciples a hitherto unbearable truth, that his Cross will reveal the nature of reality and change it for them. Jesus has revealed and repeated through this farewell discourse that love is the means of relationship with him, with the Father, and with one another. Love, however, is here not love simply as usually understood, but the love demonstrated in the foot-washing (ch. 13), and the love of the Cross. The Spirit he will give those who follow him creates a community, not just with each other but with him, and hence also with the Father; to be in that Spirit is not merely to have the capacity to know one thing or another about God, but actually to participate in the being of the God to whom the Creed attests and the Cross glorifies, and to receive the kind of truth that is living in that love which is the world’s deepest reality and deepest need.
Implicit in Dean McGowan’s comments this week is that in John’s gospel, the Spirit is given on Easter evening, rather than fifty days later (20:22).