I'm on the phone here, so this is gonna be a bit staccato. Feel free to ask followup questions.
You know, one of the amazing things about a lot of religious people I know is that they know their stuff down amazingly well. They can quote verses and lines, reflect upon the history of those concepts, and on and on and on. Me? I just remember the abstracts. So I often go shuffling around books, and Google, and Wikipedia, and forums, and call this person and that, all in hopes that I don't go making myself look like an idiot.
In case you can't tell, that's a caveat there, saying don't take my word for gospel.
In the Kitab-i-Aqdas Baha'u'llah writes . . .
It is inadmissible that man, who hath been endowed with reason, should consume that which stealeth it away. Nay, rather it behooveth him to comport himself in a manner worthy of the human station, and not in accordance with the misdeeds of every heedless and wavering soul.
Basically that translates to "alcohol and drugs are bad and just because all of your buddies are doing it, that doesn't make it alright for you to do so as well." There is of course the conventional idea that if a drug is being used for medicine, then it becomes alright.
If you go look at religious writing and theological writings, at least in Abrahamic faiths, you'll often see a them when it comes to religious laws that boil down to follow them for a combination of reasons from a mix of A) Because we say so, B) Because it's good for you, even if you can't see why, C) It's a test of your faithfulness, and D) It's a way to exhibit to God your faithfulness.
I've strayed. I've been naughty. Now I'm trying to be less naughty. I'm taking it in steps though, because as much as I would like to, it's very difficult to change overnight. For instance, I'm having a very hard time giving up listening to gossip and engaging in partisan politics (two HUGE Baha'i no-nos). I'm giving up alcohol for pretty much all four reasons.