You're right. I tend to assume that everyone takes an interest in their worldview, and can argue about it. It seems incomprehensible to me that someone could not be deeply engaged with their own beliefs--but then I have these paradoxical conversations where I learn that no, many people have no idea what exactly they believe or why it's that way.
It seems to me that religion is something everyone ought to be challenging, because it often includes strong moral directives with enormous impact on our lives.
I agree, but with the recognition that people have differing capabilities of critical thinking. As an example, I get extremely fed up with people that use computers with no understanding of even the basic principles underlying their use, to the extent that they cannot troubleshoot the smallest of unexpected behavior; but I guess the majority of people fall into that group, and that's why I spend so much time fixing computers for friends and family ;).
In Islam, there are well-defined requirements with regards to the amount of knowledge a lay-person is required to attain. On the matter of beliefs, theology, cosmology, etc. the criterion is something like, "the subject must be studied sufficiently to be able to remove the doubts that are a person is capable of understanding". So for example, an illiterate Muslim bedouin is only required to understand the analogy between footsteps in the sand that indicate on the presence of a person having walked and the wonderous creation indicating on the presence of a creator. On the other hand, a Muslim that has a Ph.D. in philosophy has the responsibility to study deeply the cosmological and other rational arguments that justify every level of belief.
The bedouin can't be faulted for not studying to the level of the Ph.D. and the Ph.D. can't be faulted for not accepting without question the reasoning that was sufficient for the bedouin.
It seems to me that religion is something everyone ought to be challenging, because it often includes strong moral directives with enormous impact on our lives.