Over the past two years I've enjoyed dipping into Charles Taylor's epic A Secular Age and James K.A. Smith's reading guide, How (Not) to be Secular. More recently I have been reading Augustine and Oliver O'Donovan, and have rediscovered this quote by O'Donovan on the Christian (and eschatological) nature of the secular, which seems to be along the same lines as Taylor and Smith:
"The Christian conception of the 'secularity' of political society arose directly out of this Jewish wrestling with unfulfilled promise. Refusing, on the one hand, to give up what it knew of God, itself, and the world, accepting, on the other, that what it knew was incomplete and demanded validation, Israel understood itself and its knowledge and love of God as a contradiction to be endured in hope. 'Secularity' is irreducibly an eschatological notion; it requires an eschatological faith to sustain it, a belief in a disclosure that is 'not yet' but is absolutely presupposed as the inner meaning of what we know already. If we allow the 'not yet' to slide toward 'never,' we say something entirely different and wholly incompatible, for the virtue that undergirds all secular politics is an expectant patience. What follows from the rejection of belief is an intolerable tension between the need for meaning in society and the only partial capacity of society to satisfy the need. An unbelieving society has forgotten how to be secular."
- Oliver O'Donovan, Common Objects of Love: Moral Reflection and the Shaping of Community, 42.