I think religion is just a name, what goes on in your heart is the real deal. There are people who are not even religious yet would not have anything to do with alcohol or drugs; it all depends on your personal belief. While some families set rules to prohibit alcohol and drugs, there is no assurance that a family member would not rebel and break the rules. It is the same with families who set no rules, there are still members who wouldn't take alcohol or substances based on personal belief. Both ways still depends on personal beliefs.
I think that better than repressing or forbidding is to explain,. When we explain what alcohol does and we show examples we generate understanding and people who get it will not drink.