Eternalism sits uneasily against most religious pictures of time, which generally treat the future as genuinely open, not yet decided, and treat human choices as making a real difference to what becomes real rather than merely revealing what, in some higher sense, was already there all along; process theology in particular was developed specifically to preserve this kind of openness against any deterministic or eternalist block, insisting that even God experiences time's passage and does not simply survey a completed four-dimensional universe from outside it.
Eternalists reply that the metaphysical reality of all moments existing does not by itself settle whether the future is determined or undetermined, since a block universe can, in principle, still contain genuinely undetermined events at later coordinates, so eternalism and determinism, though often discussed together, are not strictly the same claim and need not stand or fall together. The dispute with presentism remains largely unresolved within physics itself: relativity is widely taken as strong evidence for eternalism, but some philosophers of physics argue a suitably reformulated presentism, keyed to each observer's own reference frame rather than to a single universal now, can still be made consistent with relativistic physics, keeping the debate active rather than settled by science alone.