Don't argue about gun control, 2nd Amendment rights, etc. with anyone who has never fired a firearm. Take them to a shooting range and let them have a fun day of shooting, THEN ask them how they feel about firearms.
The best thing you can do for the defense of your RKBA is to take non-shooters shooting.
Indeed, I've added two firearms to my gun collection dedicated exclusively to first-time shooters. The first is a semi auto .22 pistol with 3-dot sights. Why 3-dot sites? Because EVERYONE knows how to play tic-tac-toe. Just line up the dots, 3-in-a-row. If a new shooter can get shots on the paper early on, that goes a long way to having fun!
The second is a 20-gauge semi-auto shotgun. Most new shooters are a bit recoil-sensitive, so for friends (especially petite female friends) who are new to shooting and want to shoot clay pigeons, don't hand them a 12-gauge pump. I made that mistake with my slender wife (who endearingly refers to recoil as "kickback") and the recoil was too much for her. She is now gun-shy when it comes to the shotgun.
Remember, those of us who love the shooting sports love them because we DO THEM. Get your non-shooting friends out there and let them join in the fun. I'd rather take one newbie out shooting than have an on-line posting war with 500 anti-gunners.....
Great comments. Well said and well directed.