To me, if you truly love one another, then personal attacks against your belief should not be taken offensive. I find it more offensive when people who are of my belief make other people hurt. I am not perfect and I am only human and in spite my efforts, I can be a bit judgmental of others, even myself, but deep down I know it is wrong.
I was raised catholic as well. I opted out at age 12 and told my mom it was making me hate God and I wanted to find my own way. I did just that. It took many years, but for me, what I belief feels right. My brother did the same, though he doesn't believe in God, well, he said he doesn't but I think of him more as agnostic than and atheist.