A reasonable religious person should believe:
scripture > modern culture
reason > religious tradition
I am looking for two questions to test for this in each religion, one for each condition. The questions should be simple, direct, and limited in scope. They shouldn't be deep or profound or depend on knowledge of another area like science. So an unreasonable religious tradition would be one that conflicts by reason with scripture or widely accepted facts in the religious community.
Applying this to Islam, we get:
Quran > modern culture
reason > hadith
A good question for the first condition would be something clearly stated in the Quran that conflicts with modern culture. This question would eliminate liberal Muslims. A good question for the second condition would be to pick some unreasonable hadith that conflicts by reason with the Quran or other facts accepted by Muslims. This question would eliminate Muslims who reject critical thinking.
The point of having this pair of questions is to quickly judge whether a religious person is worth talking to. If they get either question wrong, then there is no point discussing any other topic with them.
I have some ideas for the questions for Muslims, but I will wait for feedback first. I am interested in suggestions for these questions for any religion.