Answering my own question: whatever else it might mean to recast the eternal as whatever is unthematisable within the current temporal order, it is clearly not a reduction to immanence as such. It is, neverthless, a kind of deliberate mistake - we can pretend that the language of resurrection-in-the-hereafter in the writings of the early martyrs refers to hopes of social and political regeneration, but we are likely to embarrass ourselves if we try to uphold that pretence in the face of contrary evidence. What follows is therefore somewhat tentative, the spinning-out of a pretence that might or might not become more real as we go along.
Let me first clarify some assumptions. The first is that the articulation of a theme must take place in the context of some temporal order. Because I am a former literature student, what I really mean by that is probably that there are different narrative approaches to time, different ways in which a given telling of occurrences will arrange them in some sort of temporal sequence. So I’m talking about time as it is figured in social experience, in the language we use to talk about the past, present and future, rather than in some more “serious” scientific or metaphysical sense. When Eliot’s Prufrock talks about measuring out his life in coffee spoons, and wonders how he might begin to “spit out the butt-ends of my days and ways”, or Marvell’s seducer in “To His Coy Mistress” dismisses the notion that there is time, any time at all, for sexual prevarication, those are examples of the sort of time-talk I’m thinking of.
Moving away from literature, the regimentation of factory workers through “time and motion” studies would be a practical, political example of a “temporal order” which imposes certain limits on what takes or can take place on the company’s time. The form of our societies is amongst other things a form of temporal order - we talk about the “pace of modern life”, its rhythms. We “have time” for some things and not for others. So a change to the form of our society would also potentially be a change of pace, a change in the temporal economy. In a different sort of society, you might spend less time doing certain things that are absolutely necessary now. You might have more free time, or on the contrary your time might be increasingly committed to currently unimaginable future goals.
Hence the temptation to understand death and resurrection as events marking the passage between one temporal order and another. Death comes when we are out of time: it puts a stop to the time we think we have, the time we occupy (“Where can we live but days?”). Resurrection would not be a return to the old times, to business as usual, but a “clothing in new flesh”, the taking on of a new form. It would be the start not only of a new story, but also of a different kind of story, a story that could not be told in the language of the “same old” story. The saint / martyr is the person whose life and death, now, for the sake of a seeming absurdity bears witness to the possibility of a future that is not projected in any of our forecasts.