Rabbi Yisroel Salanter would constantly say that the root of all transgressions is a lack of Emuna.
It comes from a failure to internalize the fact that there is a reward for doing good and punishment for doing wrong.
It comes from a failure to visualize how an evil person suffers in Gehenom while the righteous are blessed with eternal ecstasy.
~ R’ Chaim Mordechai Katz zt”l (1894-1964)
Emuna Daily 
How sad that most (non-Observant) Jews are not taught this fact and have no idea it’s the Truth.
Not only that, many Jews believe that the concepts of “Heaven” and “Hell” are not part of Judaism!