The question is can you see him as the better version of himself not drinking beer, or do you see him as the beer drinker? Sometimes when we want someone to stop something, we see the bad and say stop the bad. But really if they knew they would be a better person without, then they could be without, but most often they do not see, and that is why. And if people remind them of the bad, bad is what they see.
To be able to inspire someone to change something, one must first find the place where they are unaffected by it, and can still love the unchanged person 'as much' as if they did change. That is the tricky part.
It's like if someone wants to lose weight, they must first love the body they are in. When you love what you already have, it changes into more of what you see in the image of love. Love is always the answer.