Here I'll summarise, re-present and then comment.
What the Archbishop seems to be saying about revelation is that if it comes to you it does so knowing you from a place you can never penetrate fully, but you explore and never finish exploring, and you revisit your own past to tell again who you are in this shift of perspective bearing down on you (glory and weight) from the beyond, and the truth may hurt. Revelation comes into the particular of our exchanges and language, and reaches in its whole as a gift, unlike any preferential spirituality. Given Jesus's impact on truth, and our lack of knowing so beyond ourselves, the transcendent must be associated with Jesus. This approach of revelation is entirely consistent with the academic purpose of searching and the unfinished search. This is entirely different from that revelation which claims to complete the unknown with a claim to the known.
Here is my rewrite of his lecture (I can do this to understand it: how anyone sat there is supposed to understand by listening I have no idea: it's good to take in ten per cent of a lecture or sermon).
Rilke the poet says that in the face of beauty comes the sense that you are being seen, not the seer.That's my reading. This is a clever piece to connect both issues of revelation - avoiding a God of the gaps - and the place of the university.
Revealed religion is not an add-on but an exposure and scrutiny from an unimaginable perspective of the self, however self-aware one may be already.
Revelation is often associated with personal claims to unique insight, without the ability to challenge, and the Enlightenment approach rightly rejects what is not open to scrutiny.
However, its scrutiny was based on too narrow a view of reasoning and criticism. Such itself would have paralysed scientific research, never mind theology. Theologian Sarah Coakley sees metaphors of veil and cloud in the rhetoric of scientific discourse because of the ongoing not-yet-finished penetration of the natural order. Eighteenth century science was also associated with Romanticism. Still, criticism as by the Enlightenment of the way revelation is used still stands.
Karl Barth said revelation shows primarily the nature of the revealer not content. God reveals God, but his unbounded freedom and an eternal will to relationship with very finite minds that become aware, not that they have knowledge to beat all other claims to knowledge, but that they are finite in the midst of being acted upon.
The Hulsean preacher pushed revelation when Eighteenth century forbears were pushed towards the reliability of natural religion open to all viewers. A God that communicated in history was unreasonable and an injustice towards those who didn't get the communication and were cut off from God. What is the use of only selective revelation?
However, divinity perceived through the natural order was not so straightforward morally. The Lisbon earthquake in the middle of the eighteenth century saw to that. So did Darwin's stubborn and blind competitive processes. What was stable was found to be arbitrary, not so different from selective revelation.
Still this doesn't solve the difficulty of selective revelation on its own terms, and we today especially do not like to give legitimacy to unaccountable authority. We also culturally prefer the individual search to the collective understanding of truth - also the opposite of the Enlightenment's collective universalism.
Back to Rilke and the gaze, act, purpose: what is other and only known right outside my own conceptual field. Revelation thus tells even of the mysteriousness of this natural world given its otherness outside the conceptual field - its investigation by the self can never end. It's thus about hesitation in the face of the other (Simone Weil) and, furthermore, I might be convinced about God the revealer, but not in how revelation might also be working in the person (or nature) who hasn't experienced revelation.
Revelation though means experiencing the self at a new level, a life-changing intensity of self-awareness. One is surprised into awareness. Revelation like this must come into history, into language and into exchange between persons. Such is not David Hume's universal one langauge divine message but rather in and amongst how people interact and come to know themselves.
This all prohibits the claim to a comprehensive knowledge. Truth is in the at least, where language has to readjust to take in the revelation - and is still incomplete. Our freedom is constrained in the freedom of the revelation and its weight bearing down on us - the Jewish scriptures' word for glory is the same word as for weight. It puts questions to us; our freedom would be to deny the revelation.
The Christian sees revelation as a moment of drastic change in the perception of oneself; one's own story has to be rebuilt and retold. Such is only the beginning for mysticism. Such is seen in the encounters in the New Testament. Saul finds a new identity: Saul persecutes, Jesus is the persecuted, and thus comes a new theology of grace - to those committed to Jesus (the persecuted).
This comes into history and language. It reverses and renews identity. One's memories need revisiting, though this cannot match the knowledge in the revealer. In the face of that along with considering Jesus's impact and our lack of knowledge, indeed being comprehensively wrong, the transcendent must be identified in Jesus. Jesus is present in the mystery of understanding me that is beyond my own reach.
Augustine's God is 'more intimate to me than I myself' reflects revelation. There is scrutiny beyond my control, more than I can see, that is never ending in my pursuit of it, and which transforms.
We don't hate truth until it then challenges who we are (Sebastian Moore, The Contagion of Jesus). You are not forced into the new identity, though in revealed faith you are larger than you were.
T.F. Torrance says that 'Jesus Christ... is the revelation he brings' (Incarnation, p.188). You are in relation to the utterly truthful and compassionate as was in history, God engaging from within history.
So often revealed religion is seen as contra to the academy, but as here described it should be supporting the need to know and unfinished nature of knowing. It's not because it is about provisionality but because it encounters with human interaction and using language.
The parallels are with intellectual activity: persistence, honesty, issues only been named and not resolved, the mind and imagination involved. this is a gift not recognised by just a preference for a spirituality.
Revealed religion is not the last pieces of a puzzle, but the whole free self-disclosure on the part of the transcendent coming into our own language: not selfish, not seeking advantage, not manipulative, but fear making in that is shows the truth in its gaze about who we are really.
At the heart of this then is both a liberty of God and a liberty of the human being in that of action and inaction. But it is also credal - he says the creeds are like a shadow in front, and a tradition: he sees such as part of the weight unlike what might be consumerist spirituality.
There is no doubt that, in some situations, perhaps stressful, perhaps in beautiful environments, perhaps in a situation of peace, that you can be hit by something unexpected, and a shift of insight. Not everything confirms the language you use at the time.
Also I am attracted to the notion that being hit by an insight is also to be hit by the unknown of the insight, that begs for further investigation.
Many a scientist and mathematician has put a daytime walk into his or her schedule, often alone, and without any predetermined inner dialogue to allow something to come as an almost unseen insight. Artists too can just sit and wait. Being hit by the insight leads on to something more, but then you have to find that out.
My only objection to this presentation is that there is a universalism offered around the subjectivity of the person, or the conversation between persons or within the person. God reveals God the pure and unadulterated. Though, to me, it is adulterated from the beginning. The scientist, mathematician and artist is no empty head, and the quest for investigation shows relative shift.
None of this, though, assumes that our not knowing is the existence of a knower, a perspective beyond which is closed. Rather, it is to get into that perspective which opens up. The struggle is opened out some more, but it does not lack access. It requires more synthesising, more opposites (dialectical talk), more grappling.
If we take Paul, the example that fits the approach offered by Rowan Williams. After his shift he was still using the language of resurrection and still had the last days perspective. His shift to spiritual body (away from body, because of experience) was awkward. It did take, according to one account, a trip into the Arabian desert to do further sorting out. He was already dealing with the Messianic claim in his rejection of Messiah if Law is to be upheld, to become rejection of Law if Messiah is accepted, and he had a guilt of persecutor that became a salvation religion of the persecuted (absolving Paul's own guilt) then transferred to all.
There is nothing that need limit this to one religious prophetic figure. Buddha too shows insight: sat under the Bodhi tree the insight comes: not from a transcendent power but from the exhaustion of the other routes and the need to pause and wait via clearing the mind. It can be a transcendent power, but the compelling weight can simply be that brain wiring that suddenly sees the symbolic dots of the language joining up in a slightly different way.
Ally that insight hit with a prophetic figure, like Jesus, and then the ethical potential also rolls out, a freedom the prophetic figure invested in transfers across to the believer to as if recommend the path, the service and the sacrifice.
My view is thus something like this: that when you grapple with things you come up a number of cul de sacs. In that anything worth the effort is a signal of transcendence (signs and signals here) then sometimes there can be a spark across the signals, or coming out of the signal. Your rested mind gets a leap across, and that transcendence possibility hits. So there is another insight. That insight may not come simply from a vast openness but from a model of possibilites already laid out: lived and thought.
What you try to do in such situations is assert the loss of equilibrium and open up the possibilities: to find an involuntary tipping point.
Then sometimes there is no such deliberate preparation. There might be stress and guilt, and other background, but even then may not be. Still an insight breaks through.
That insight is within the natural chaotic and ordering systems around us: the contingent and specific possibilities of the evolving world and that environmental constraint which forces some kind of regulation and similarity of outcome. The revelation insight is in there, and the old deist naturalism is now one of those cul de sacs. Life itself is dynamic that it leads to new insights, out of the freedom of the unknowing of systems we now recognise as chaotic when equilibrium fails.
The delivery may be from God, or a God: but here the suggestion is that if it is transcendence (and it must be close to transcendence) then that is something found in the nature of the world as something with freedom, change and potential chaos. It is as much an inside agency as an outside agency that penetrates and shifts about the human symbolic meaningful world.