The practical issue is that religion is not a single institution that can be switched off; it is a set of practices tied to meaning, ritual, community, and mortality. Even where formal attendance falls, belief and practice often adapt rather than vanish. Demographically, religious populations remain strong in many parts of the world, and secularization is uneven, not universal. So by 2100, religion may look different and be less dominant in some societies, but predicting its disappearance confuses change with extinction. The other side needs more than a trend line; it needs a plausible mechanism for total erasure.