Most Orthodox Jewish people do not really believe in Judaism. No reasonable adult can possibly believe in that kind of stuff. So what Orthodox Jews actually do is pretend in what they believe. Why? Because they want to maintain a Jewish identity and they realized a long time ago that religion is the most efficient means of securing that identity. But Jewish people never talk about it because they have kids which they pretend what they believe in is real. Jewish parents know that if they simply told their kids that Judaism is make believe then the kids will not be serious. So what parents did was told them that Judaism is real so that it will motivated the kids. And the children keep the restrictions and obligations of Judaism because they think it is real. However, once they become adults they realize that Judaism is really false but they still maintain a Jewish identity because that is what they are used to. And they stay silent, no one talks about it. When they finally have children of their own they teach them these lies at first so that they can become just like their parents. And this has been going on for thousands of years. No one talks about it.
There are two kinds of outcasts on this never mentioned secret. The skeptics and the yeshivash guys. The skeptics rebel against Judaism because they noticed it is not true, but they fail to noticed that Jews also know it is false but just pretend it is true. This is precisely why Orthodox Jews despise skeptics because the skeptics are close to breaking open their secret. But in actuality the skeptics and Orthodox Jews believe in the same thing. And then there are the yeshivash guys. Yeshivash the guys are just so stupid that they never realized that Judaism is false. At between 18 and 20 Jewish people start to realize this secret of Judaism, except the yeshivash guys. They are the dumb ones who never got this message. So they are so devoted to Judaism because they think it is real. While the normal Jews they know it is not real so they are not devoted to it. If you watch a normal Jew daven and a yeshivash guy daven you will quickly note the difference. The normal Jew only davens not because he believes but because he is maintaining his Jewish identity. Since he does not believe he cannot be serious and there is no devotion at prayer. The yeshivash guy is full in devotion because he actually believes.