Sometimes you take a job for the money, sometimes you take it for the location, sometimes you take it for the script; there are just a number of reasons, and ultimately what you see is the whole landscape of it. But I can tell you from behind the scenes - that's what it is, as an actor.
For many people, the reluctance to embrace Christianity is as practical as it is intellectual. They want to know what the benefits of Christianity are, or what's in it for them.
It is not necessarily true that expensive experiments are not worthwhile doing but there are plenty of rather cheap experiments which are certainly worth doing.