"religion is not enough" is the npc escape hatch.
People we might consider as npcs have basically convinced themselves that religion is enough. It's not that they have no spiritual questions, it's that their religious exposure continues to ingrain them as convinced that it has the answers. Think about how heavy the work is to maintain the conditioning. It has to ve once every week, basically, at minimum. These are usually the people that were "lucky" in terms of finding a palpable degree of acceptance and belonging.
They look at their religion as their license to exist. Without it they have no license. You have to think of what kind of insanity that has to be. But I remember finding it as normal as sliced bread.
Funny that anything which deviates from these norms (a weekly indoctrination, a license to be) is considered a cult ("occult" or hidden knowledge)
Anyone whom cannot find stability in religion imo is not an "npc" ... while everyone who finds their "place" in religion ... is an npc. Not because it's wrong to have beliefs, but it's wrong to think that knowledge is supposed to be anything other than the evident