The friend isn't a bad person in my opinion .. he just doesn't understand addiction. If you can't make him understand that you don't want to drink .. you'll have to avoid him. If he's a real friend he'll realize in time he hasn't hung around you for a while and think "Wow, I was wrong." and maybe stop pestering you to drink. I don't know.. all I know is a lot of people don't understand addiction.
Good luck.