Study of 94k Americans: Irreligious blacks do much more drug selling and theft than religious blacks

This study, using a sample of ~94k teens and young adults, examined the link between religiosity (church attendance and saying religion is important in their life) and drug selling and theft. The researchers found a robust inverse association for various age and demographic groups. The magnitude of the link was considerable for black males and females: the incidence of drug selling and theft was between 1.6 and 3.3 times higher for irreligious blacks compared to their religious counterparts.

Of course, a correlational study can't tell us anything about causation, but this study provides pretty good evidence that one finds more law-abiding blacks at church, and the Church has always been a central institution in the black community.