It seems like this is confusing The Church with a church.
Notre Dame Cathedral is a church, but you could burn it to the ground tomorrow and it wouldn’t have hardly any impact at all on the persistence of The Church.
Such is claimed, but I suspect that this is a misleading truth. Christianity is an extremely successful religion, but if it were less popular and Notre Dame was one of only a few church buildings (even, just one of a few with that level of grandeur), then burning it to the ground would indeed have a profound impact on the persistence of The Church. For those religions with a single temple, the destruction of that building is more than merely traumatic, it is catastrophic. Christianity only avoids this by having so very many buildings, many of them as spectacular as Notre Dame.