I'm not convinced that "put in more research effort" really deals with the problem because it essentially defeats the point of asking a question here in the first place. We maintain that good answers are well sourced and verifiable - in other words, the products of research. If we also require question-askers to put in a load of research before their question is admissible here, we get into a situation where they research the answers to their question themselves and therefore there's no point posting it on this site, since their "problem" is now solved.
Of course there is a subtle difference in some cases where answerers may have better knowledge of where to look for answers, or better access to source material to refer to. But we do need to be careful that we don't end up with questioners having to go and do so much research that they no longer need to ask the question.
My view is that the onus needs to shift in cases like this. If the questioner isn't really interested in what a particular denomination believes but is interested in Christianity generally they should still be able to ask their question. A good answer would then explain the different views; "Catholics believe X, Baptists believe Y, Seventh-day adventists believe Z". That's not to say every answer has to address every denomination's view from the outset. User A might answer regarding one denomination and user B about another, with User M eventually coming along and providing a summary answer to pull things together. (Or users could edit the first half-decent answer to add information about other denominations).
It's a difficult balance; setting the bar too low results in hordes of rubbish, spammy questions. But insisting that questioners research the subject themselves before asking a question defeats the point of asking it to some extent. Perhaps the real question here is not what to do, but how much research should we expect a questioner to do before they post their question?