Being wrong

I had a conversation with my youth minister that went something like thins
Me: Is it a sin to be wrong?
Youth Minister: Um, no, I don't think so
Me: Then why is it considered a sin to be the wrong religion?
The youth minister never really answered that.
I remember when I was (Very) young, I thought anyone who didn't believe in "The Right God" were evil. I know this seems very extreme, but unfortunently some people have opinions the aren't all that different.
For that reason I think that it is not a bad thing to be a different religion than I am, and if there is any judgement by god, they will not be judged by their faith but their deed. We have all been wrong on pretty major thing. I have no doubt I would be Jewish, Muslim, Atheist,  Buddhist, Hindu, or whatever religion my parents were had I been into a different family.
Incase that this post is confusing, let me explain:
When I was young, I was wrong about something that I thought very major (Thinking anyone a non-Christian were "Bad" and because I was Christian I was "Good"). Everybody has had similar misconceptions, so it is therefore not a sin to be a different religion, or else it is a sin everybody has committed.