Need to clarify assumptions:
Assume humanity has to essentially start over, recapitulating previous stages - tribes, city states, kingdoms/empires, nations, global expansion (if possible).
Assume the biosphere recovers fast enough that it is not a barrier to civilization's redevelopment.
Assume nearly all technology is forgotten and much of science is lost except some basic concepts - needing to be redeveloped.
Assume religion again gains dominance over understanding of the world, but remembers being deeply challenged by science - and so suppresses science and technological change for centuries, while preserving some key bits (like germ theory, maybe surgery) that can be controlled to elevate the status of religion.
Assume easy availability of concentrated metals (ruins of cities) accelerates the process of recovering early civilization, but delays development of mining and refining technologies, preventing a return to hard to get fossil fuels and delaying metallurgy and other material science.
Based on this, civilization can at least recover to pre- enlightenment levels. And once more, reform within religion will be key to going beyond that. Possibly this time organized religion will try to retain control over science to suppress the potential harm to religion and control what technologies get released that might threaten a static hierarchical society. Long term, that will fail, but could work for centuries. Technologies might be limited to the powerful, with most people trapped on small farms that barely feed them with little surplus. Not so much a "dark" age of ignorance, as a "slow" age of tightly controlled progress, where stability is paramount, improvement of the lives of the masses a distant last.