It is not worth trying to prove or disprove Torah, God, etc. There will be evidence for both ways and people will side with what they want to side with.
So why do we believe?
1) We believe because our souls want us and inspire us to.
If your soul does not do so, then you either don’t believe or are struggling with it.
2) We believe because those who love us train us and nurture our souls to believe. A good person must have a first allegiance to the training of those who love him.
Is this not true for every religion?
Yes it is. And so what. If you were raised Jewish, your first allegiance is to be Jewish. That is the team you were put on.
Do people sometimes change teams? Yes, but you need a very good reason to do it. Converts find these compelling reasons. If a person is compelled in a certain direction, then they must carefully explore it. If not, just stay on your team.