Christians and Mary Jane

Upon rolling some joints at school, my friends inquired what my thoughts were on God and whether or not he thinks it is ok for christians to smoke pot. They were curious because they themselves are christians and they did not wish to do any wrongin' towards the Lord. My response, while not condemming, I believe was the right response. Instead of answering their question I asked question myself saying "If smoking weed WAS wrong in his eyes, would you quit? Cause if you wouldn't then it doesn't matter." I think it should be obvious to anyone whether or not God approves of grass, otherwise they wouldn't hide it, stash it, talk quiet whenever it's mentioned, cover their heads, lower their heads or constantly give reasons for why it is OK whenever its place in their lives is questioned.