In my opinion, the variants of Christianity in the United States today are similar to cowpox as far as virulence goes, radical Islam similar to smallpox, and Reason (with a capital 'R') sort of like a vaccine.
I would personally just as soon everyone who's not naturally immune be infected with cowpox (Christianity) so that they develop an immunity to smallpox (radical Islam). Indeed, before the smallpox vaccine, people intentionally exposed themselves to cowpox in order to achieve smallpox immunity.
I prefer this approach to the vaccine (Reason) for two reasons. First, the vaccine doesn't seem to work very well. It seems impossible to innoculate some people and many of those that are innoculated still seem to become infected anyway.
Second, the vaccine of Reason has, in my opinion, at least one serious side effect. Those who do develop immunity seem to become relatively infertile. I realize that many on the Left think that having fewer children is a good thing, but I don't for a variety of reasons that I'm not going to go into here.
I say this as someone who has natural immunity (I'm not particularly religious and not Christian), but consider the disease of cowpox a small price to pay for immunity to things that are worse.