Which question can you ask to find out the most about a person?

Ooh good question, @Hope, I'm unsure haha. Just one? XD

"How would you describe yourself?" could help a little sneak-peek. (Although it's worth mentioning that sometimes people miss seeing themself the way others do) 👀

His or her beliefs, the way he/she expresses feelings, his/her fights, how does he/she see the life? and how does /she face problems..

This is an excellent question.

For me I think I would certainly ask

"What do you do over a day?"

Sounds mundane I know. But you can underatand a person through this question because they most probably will tell a long story.

What are your dreams?

What do you think are 3 of your strengths and weaknesses?