Maybe they are being aggressive because, in announcing his goal to read the thing from cover to cover, he announced that it was "sick, immoral", and then also boring and irrelevant. Perhaps they should turn the other cheek and all, but if your Holy Book is described in terms that would be just as suitable for 120 Days of Sodom I can't say I'm surprised at the aggression in kind.
Time was when I would have agreed with Nailit's attitude but on reflection it's neither helpful nor even accurate. I don't agree that a surface reading of the Bible, especially one motivated by distrust, can ever be enough to undermine what is, ultimately, a deeply personal matter.
None of this is to say that I believe in a God, Christian or otherwise. I just don't see the point in being a dick about that.