I would have to agree with the comment already made that controversial isn't a fixed description, one person's fact is another person's fiction, I do however think that there is a limit to which you can challenge any peron's normality before you hit the walls of their mind box and with not just Christians but with believers in all religions, I also class science as a religion because in all essence the the hunt for "truth" reveals "facts" which become enshrined dogma so much of the time despite those facts being a basis for a kind of understanding and not neccessarily written in stone, a conflicting view is percieved as an attack on a stability that the religion has brought into their lives, a surrendering to a higher power (for want of better words) which allows them to quantify and justify their life and actions so when you threaten to disturb the very foundations of what a person feels makes them who they are, you meet extreme resistance.