Most gangster movies, though they involve people doing terrible things like selling drugs and murdering competitors, are built on a Judeo-Christian ethic-for instance, the scene in "The Godfather" where Michael Corleone's thugs kill off his enemies while he attends his nephew's baptism and becomes, in two senses of the word, the godfather.
The main characters in these kind of movies tell themselves that they have good reasons for their evil actions-they are taking care of their family, for instance. Biblical values of trust and respect are important, greed and gluttony are bad, and family bond...
