This is like looking at the smoker and telling them they shouldn't smoke because it's bad for you... well sort of, but bear with me.
I know we all know now that smoking is bad for you and many people don't know that Aspartame is bad for you but if they wanted to know they would research it themselves. If they were concerned about their own health, they would know like you know. Not because anybody TOLD you but because you cared to find out and you made your choice as to what to believe.
How do you know which religion is THE right one? How do you know what the truth is? You research and make your decision based on what you feel in your heart to be true.
No one will do something just because someone told them to (or not to) unless there are consequences, and until they see the consequences for themselves, they will not change their actions.
I have read that even when they are presented with the overwhelming information (as with smokers) that many will still make the same detrimental choices. The deciding factor is an emotional one, not a factual one, that incites people to make hard changes in their lives.
Bear with people, spread your truth with a smile, and let everyone make their own choices.
Peace & Love.