Doing so can take what for someone like yourself can be a doubt free and comforting existence and try to throw spanners into it. If the person is not a deep thinker they likely would ignore me and be okay. If it is someone like you though I think it can do more harm than good.
For me, you asking probing questions would not end up doing more harm than good.
I consider myself first and foremost a 'truth and wisdom seeker' (see my Hive profile). As such, I do not seek nor desire a 'doubt free' existence. With that said, I do not desire to interact with folks whose primary goal is to sow seeds of doubt -- not much fruit to be had from those interactions. However, I am happy to engage with fellow truth-seekers. I used to teach a Sunday school class called 'Difficult Questions' where the aim was to invite folks to bring up those theological issues that they have genuinely struggled with. The presence of evil and pain & suffering in the world represent a couple questions folks commonly struggle with but might not have the courage to grapple with.
This is not to say that all such 'difficult questions' can be answered. Many times, our exploration of a specific question uncovered even more questions. The point of the class was not to provide 'answers' per se but to say that it's okay to have questions and to explore the ramifications of different viewpoints, even if we end up with no definitive answers. We should never fear honest inquiry.
If I am believing a lie or adhering to a belief system that misrepresents or misconstrues the 'truth' then I would rather have that fact exposed, so that I can abandon falsehood and seek truth along a different path. That is why I welcome genuine questions about Christian doctrine and theology, Biblical worldview, veracity of the Scriptures, etc.