I can't imagine a world where we all agree on everything. I think we choose life partners based on shared interests but also with some sort of challenge thrown in, I'm not talking about marrying a drug addict hoping to change them here, but someone who presents a good sounding board, who has their own mind and will challenge certain behaviours or views you hold in a way that makes you grow as an individual and also as a couple. To be with someone who agreed with you about everything would be boring and stunting [or maybe that's just me

].
I think you can challenge a person's faith without being insulting, it's about word choice and attitude. I've read some of the comments on religious articles that you find on say the Guardian website. There are those who will say 'so does this magician live in lala land with the Easter bunny and the tooth fairy?' and others who will say 'why would a God let there be war?' - can you see the difference? I'm not offended by the first question but it does show a lack of respect for other's views. I find it hard to be offended actually on the subject, people being flippant says more about them than you or the subject in question.
Are we offended when people call LFC all the four letter words they can think of - no [speaking for myself]. But mock the loss of life at a football game and I'm very offended. Muslims were more than offended with that cartoon, years ago, with the turban depicted as a bomb and I can see why some would be, others may have laughed but to a devout Muslim it was disrespectful. No need to want to kill the artist though, that was an over reaction imo.
The best way to convert someone to your way of thinking [if that's what a person wants to do] is to live by example.