Opinions?. I''m asking for a friend. Thank you
There's no command in Scripture against the use of cannabis, so the only real way to use Scripture here is by comparison to alcohol. Is the drinking of alcohol a sin? No. However when alcohol becomes a problem, then that's when sin enters the picture. It's not the drinking of alcohol, but rather our own thoughts, behaviors, words, our habits all associated with the consumption of alcohol that ends up being an issue. And so, on some level, this boils down a lot to individuals--if you can drink responsibly then there's no problem, if you can't drink responsibly, then that is a problem.
On top of this, there is the question of civil law. While where I live marijuana is completely legal, in most places around the world cannabis usage is against local laws. As Christians we should be respectful of the laws of where we live (obviously, there's an asterisk next to this, because not all laws should be treated equally; as St. Augustine says, an unjust law is no law at all).
Which is all to say, it might be sinful for one person to smoke cannabis, but not for another person. In the same way it might be sinful for one person to drink alcohol, but not for another.
Beyond the moral question, it's worth also evaluating the question of wisdom. After all, "All things are lawful to me, not all things are profitable to me" as the Apostle St. Paul says. Whether something is sinful or not doesn't necessarily translate to whether something is wise or not. There is, after all, nothing sinful about drinking two gallons of soda every day, but that doesn't make it a wise thing to do. And in this case, it becomes a matter of discernment for oneself.
Speaking personally, I do occasionally partake of cannabis, almost always a small amount just before I lay down to sleep. I find that it helps me sleep better and helps with some of my chronic back pain that flares up at night. I'm not getting baked though, and that's chiefly because I have on a couple occasions gotten pretty high and I didn't care for it, I wasn't prepared for it and it caused my anxiety to jump through the roof. So I try to be more responsible for myself.
As such, ask yourself if you can legally consume cannabis, and if it is, the only one who can really decide if it's okay or not for you is you. Now, that doesn't mean ignore the advice and wisdom of friends and family or anything; only that there is no commandment on this, and that makes it a matter of your own conscience and discernment. See what the Apostle says in, e.g., Romans ch. 14.
-CryptoLutheran