Absolution Gap by Alistair Reynolds

Hard SF, third in the loose triad started with Revelation Space and Redemption Ark.

All of these have been hard SF novels told partly through religious metaphor. Or, more precisely, in fragments of mostly Christian mythology reimagined through a positivist, scientific lens where the end of days happens on a galactic scale, and it's ancient, silent, species-killing machines we're afraid of. After reading all three massive books, I'm still not sure what I think about it – about how successful it is as a literary device, or how I feel about it personally, to the extent the two can be pried apart. I do think it's all quite shiny keen cool, and that this is hands-down the most imaginative, whackjob awesome worldbuilding I've seen in a long time. Neutron stars turned into computers, living oceans that reshuffle brain enwraps when you swim, indoctrinal religious viruses.

Not for everyone, but if it is for you, you can't do much better.