Many religions require the use of drugs, including psychedelic drugs, in various religious ceremonies. This obviously conflicts with laws against the use of drugs -- so what should be done? Should the government prevent such usage, or allow it as a religious exception? If they prevent such usage, then they may be preventing an important part of religious rituals. If the Catholic Church could get exemptions for wine during Prohibition, then why should minority religions today labor under greater burdens? On the other hand, if these drugs are safe enough to allow religious exemptions, why should only particular religious people be able to skirt the laws? What would be "inferior" about my secular desire to use psychedelic drugs to investigate the nature of religious experiences?
We're bumping up against a real problem when it comes to accommodating religious believers: if it's so easy to make believers exempt from a neutral, generally applicable law, it can only be because no one will be harmed, but if that's the case then why are the rest of us prohibited from the behavior as well? If no one is hurt by believers taking psychedelic drugs in a religious ritual, what is the rationale for not allowing me to take the same drug at home? On the other hand, if use of such drugs is so dangerous that I have to be prohibited from doing so, then surely it's too dangerous to let believers use it.
One possible argument here is the low numbers of believers being exempt from the law -- if lots of people were engaging in the behavior, there would be harm. That's not unreasonable, but now we are implicitly conditioning the religious exemption on the religion remaining a minority faith. If the religion suddenly became very popular, would their exemption be in jeopardy? I doubt any defender of accommodations and exemptions would agree to that, which means that the argument from low numbers is really just a rationalization that can't be accepted.
Doesn't religious exclusivity of such exemptions have the effect of promoting irrational thinking? The government is basically saying that if you want engage in some prohibited behavior, you may be exempt from the laws against that behavior if you can prove that your desire is based on the belief that your ancestors were instructed to do this by spirits or other supernatural agency. If, however, you only want to do it after a cold, sober comparison of the risks and benefits, then we'll throw you in jail for trying. We might exempt you from the law if you can make a credible argument for the idea that you think you're obeying the instructions of gods, but we'll imprison you for decades if simply think you have rational, secular reasons.
How does that possibly make sense? If you say you killed because a god told you to, the best case scenario for you is to be found insane. If you say you need to use psychedelic drugs because a god told you to, you might be allowed. If you say you killed because you have good reasons to think your life was in danger, then even if you were wrong you might get off clean; if you say you use psychedelic drugs because you have good reasons to think it helps your mental health (or marijuana because you have good reasons to think it helps your physical health), then even if you are right you're going to prison. Am I mistaken in thinking that there is something very wrong in all this inconsistency?