O.K. I've got trouble with linking the theme of "natality" to Christianity, since for all intents and purposes Arendt was a (Jewish) atheist.

It's purport rather seems to address the historico-ontological problem of the sources of initiative and the problem,- (perhaps here with a residual Jewish inflection),- of generations, which traverses any question of historical justice.

But "natality" is precisely the figure of political hope, just as the political is the proper "home" of finitude and worldliness, (in her deviant Heideggerian/existential account). And that does not mean the constitution of a "plural we", but rather the "we" of "plurality", spoken across differences and otherness. And she makes a distinction between work and labor, which accords the latter, in the form, e.g., of scholarship or art, a role in the formation of the public sphere qua site of the political, which, as the "space of appearances", i.e. of the manifestation and display of both self and other in their common belonging to the world, is the only site that reconciles us with or compensates us for our finitude and mortality.

Her criticism is directed against any philosophical/theoretical conception of politics, reverting to an idealized Hellenic notion of the polis and a partial rehabilitation of the Aristotelian conception of praxis, just as Heidegger attempted to retrieve the pre-Socratic sense of Being to challenge the metaphysical tradition. Her puristic conception of the political, which, as itself "work", is at some considerable distance from any actual political "action", stigmatizes the invasion of politics by "the social", which at once criticizes any administrative/economistic/instrumentalistic reduction of politics and the (over-)moralization of politics.

Any morally tolerable politics requires the delimitation of the political from the moral, the public from the private, for the sake of both. That she figures the private in terms of the unknowable "darkness of the heart" echos Hegel's reading of "Antigone".

John,
Hannah Arendt used the notion of natality to refer to "the new beginning inherent in birth". This Arendt holds, is the ground of the distinctively human capacity, "the capacity of beginning something anew, that is, of acting."

'Natality' or 'new beginning' is a central metaphor throughout her works. Not the inevitability of dying but the promise of giving birth to the unexpectedly new was Arendt's refuge against an overly determined world.

In The Human Condition she writes:

The miracle that saves the world, the realm of human affairs, from its normal ;"natural" ruin is ultimately the tact of natality, in which the faculty of action is ontologically rooted. It is, in other words, the birth of new men and the new beginning, the action they are capable of by virtue of being born. Only the full experience of this capacity can bestow upon human affairs faith and hope, those two essential characteristics of human existence which Greek antiguity ignored altogether.....It is this faith in and hope for the world that found perhaps its most glorious and most succinct expression in the few words with which the Gospels announced their "glad tidings": "A child has been born unto us". (p.247)

I suspect that there is a strong theological strand running through Arendt's texts--ie., Athens and Jerusalem.

The "miracle" in that heavily rhetorical passage is newness, historical-futural "change in the essence", that results from the unexpectable, unpredictable growth of the effects of political action; the contrast implied is with the ancient wonder at the shere existence of the world, as well as, with technocratic efforts at administrative control. But the overriding theme there is precisely worldliness, in contrast to any religious transcendence/denial of the world.

She did write her doctoral thesis on Augustine, but I've never detected any orthodox theological hankerings in her, except in the most unmoored way. Rather I think it's that her work operates at some considerable distance from any political engagement, though it ostensibly is preoccupied with it: a residual idealism rather, a spectactor's stance.

John,
It is through the success of new beginnings put into motion by political speech that the individual marks their presence in the world, and extends this presence into the future through a process of shaping, defining, and circumscribing.

It is in the political arena, in this venue of voice, speech, and action, that new beginnings, new possibilities, commence. Arendt emphasizes a world of "being-with-others," of natality and plurality, where diverse group of human individuals will spontaneously get together to discuss political action in consort.
political action in consort

Yes, but that's just an entirely secular, worldly conception of the political. And I'm not even so sure that it's the success of "action" that's definitive. IIRC, she defines "praxis" as acting without ends, rather than Aristotle's action which has its end in itself, eliding any means/end relation. Successful action would be the paradigm case, in that its very passing away would be its retelling. But wouldn't failed action or even violently repressed action nonetheless contribute backhandedly to the constitution of public/communicative "power"? That might be why she lays stress on "forgiveness" as a distinct condition of political action. "Power" is oppposed to violence, (as well as natural fatality), hence set against sovereignty, as well as theory, oddly enough. (Sheer idealism?) It strikes me that I don't recall her ever addressing Hegel's "Philosophy of Right"/theory of state, when he would seem in many ways an exemplar of what she sets herself against, which suggests to me a latent, backhanded influence.