I do not believe it is right to use marijuana "recreationally" to achieve an altered mental state, anymore than I believe that is acceptable to do with alcohol, cocaine, or any other substance. Drunkenness and sorcery is sin, period. However, I do not believe, as a Christian American, that it makes any sense for such substances and such behavior to be illegal in the sense that incarceration is possible.
All that illegalizing drugs has done for our society is to prosper gangsters and thugs, who use their power and money to violently destabilize culture, even entire societies (like Mexico, Burma, Columbia, etc.); and to burden society with the cost of building, maintaining, managing, and supplying prisons, largely, for drug offenders. When those offenders are released, they are, generally, more violent and less capable of succeeding in "normal" society than they were when they went in.
Our approach to drug enforcement looks to me like the proverbial shooting of oneself in the foot. Surely, there has to be a better regulatory model than what we're doing now! Prohibition was a disaster, and so too has been the "War on Drugs." We should move from criminalization to regulation yesterday.