Marijuana, on its own, does not lead to hard drug use. I know many responsible and highly accomplished people who use marijuana. You do, too, but it's a secret. When we focus on responsible, constructive behavior in our lives, then we can apply those values in all of our relationships with things and with people. That's how we learn to make good decisions.
Some faiths prohibit drinking coffee.
We just approved soda machines in our schools despite the knowledge that the stuff contributes to tooth decay, obesity and possibly diabetes. Adults may buy and sell tobacco knowing full well that its use is directly linked to emphysema and cancer. We know that there is responsible and irresponsible adult use of alcohol. Then there's marijuana - mild in comparison to the physically addictive drugs it is associated with in our laws. Life, liberty and the pursuit of happiness - ring a bell.