To be honest, Christianity and the figures therein are much too widespread to be protected by a no-joke taboo anymore. It's basically public domain. And anyways, Jesus and the like are historical figures, and as such are not exclusive property of any religion. I don't know about anybody else, but I'm not going to tailor my speech to cater to the sensibilities of anyone should I deem it unreasonable to do so.
Regardless, it completely depends on the decisions of the DM. Is it easy through the method described by the DM's Guide? Yes, absolutely. Through a self-written method intended to confuse and frustrate? <_< Let's say not.