Personally, I think lots of these questions make it through the close filter. In my experience, questions are closed when they have several problems. Some of these problems can be fixed by editing a few things and others require a heroic effort. Closings questions should signal readers to identify the problems and either fix them or move on. Perhaps it would be best to think of such questions as Under Construction:
Let's take a look at the question that Monika commented on:
Would the bible draw parallels between the spies returning from Canaan and modern biblical criticism?
The close votes seem to be following this line of reasoning:
This is really calling for speculation. It also isn't really about Christianity.
So the problem is at least two-fold. If I were to edit the question, I'd also fix the capitalization of Bible in the title and maybe the tags as well. I also don't understand what the question is asking. This is particularly a problem since we might have several interpretations of the question which result in wildly different answers. In other words, it's a question with problems. Ideally, we will start fixing them.
On the general question, I don't think that closing "speculative" questions (if that's really what the community is deciding) will prevent us from having interesting questions. It might make certain types of questions more difficult to ask. Take for instance:
Is Knuth's 3:16 project unique?
Great question: well written, interesting, thought-provoking, and ... not about Christianity. I seriously debated whether to vote-to-close or answer. You can see which I picked. I'm not sure what it's about, honestly, but I want it on our site.
In my opinion, good questions follow all the rules and great questions break just one. Also, they need to be lucky enough to be the right question at the right time:
Luck is what happens when preparation meets opportunity.
(No Oprah didn't originate that and Seneca probably didn't either.) A great question can win the lottery despite violating some rule or another. Not every question can be a home run, but when we do get one we don't want it to be of the Little League variety. These questions stop being fun and interesting when everyone is trying to ask them and few people are able to pull it off.