Anything that you allow to take control of your mind and over your body is a sin. Not having control of yourself is not good for your soul, mind, and spirit. The bible does not say anything about smoking cigarettes, pot, and using drug that alters our mind, so do also you think that is not a sin? Come on man stop looking for excuses. Anything that we become addicted to and can't control is not from God, for the only one that wants to control our mind is the evil one. God has given us a free will, but with that free will there is lots of responsibilities and self control that comes along. Someday we will have to answer God why we let the enemy take our free will away from us.