Profess I can understand.. if I truly believe that my friends and family will experience eternal torment if they don't say/do the things they're expected to to avoid that destiny then I don't think I'd be able to help myself from trying to convert them.
In fact I know I wouldn't I used to do it.. I was a youth group leader, I was in the worship team, I preached from the pulpit.
Not much different than stopping a friend from drinking then driving.
So while someone trying to convert me can be somewhat annoying at least they have the courage of their convictions, so I find it hard to really get upset about it.
It's when some try to enforce their beliefs on others through laws that it goes too far.
As for defend, it was questions like "why do I actually believe what I believe, how do I defend my beliefs to myself" that led me away from my faith. So if people want to do that let em!