When people say they have lost their faith it is because their faith at the beginning was too weak to withstand any challenges.
When your perception of God does not extend beyond a basic level, you can't deal with them very effectively when you grow up.
We basically found that people who went as believers to the concentration camps remained believers and vice versa.
In the second part of Tanya, Shaar Hayichud, it deals with understanding God.
Not that you will get to know God but at least you have an order of magnitude.
It's a mathematical term.
If you're talking about something expensive, what order of magnitude is it, hundreds or millions?
A person who learns the Tanya gets to a different order in his perception of God.
–Rabbi Adin Steinsaltz
From an interview with Rabbi Adin Steinsaltz on the Tanya