Marijuana and christianity.. is it always gonna be a sin?

I've tried it, but no longer would. Plus im christian it would go against my beliefs if I continued to do so. But the argument for that IS ONLY because its illegal, otherwise i don't see how it would be a sin according to the bible... alot of people claim cannabis is harmful for you it causes this and that.. and if you believed that cannabis did do harm to your body then it would be sin.. but people claim its harmful effects when in reality thats not the case. there are recent study that actually show how THC can eliminate precancerous cells and stop the spread of cancer.. so that being said lets say if marijuana was LEGAL, would it be a sin to partake? obviously if you abuse it your in the wrong, but what if you used it every once in a while? i would see it as being a benefit for you health.. therefore it wouldn't be sin. right?