On that subject the blog undivided looking touches on using applied history and theology to rationalize Christianity. It appeals to my sense of mrationality at least.
I took a look at that blog, but it doesn't seem historical at all to me (for example, I can't think of any historian that dates the synoptics to before 70 AD). I also can't say I'm a fan of the way he treats other denominations of Christianity as non-Christian religions.
For a good historical look at Christianity, I'd recommend people look into the Religions of the Ancient Mediterranean podcast, the NT Pod podcast, or, for the old testament, the writings of Mark S. Smith (you can also find lectures of his on Youtube).
I would recommend that blog as well; it is among my favorite places on the internet. Aron's writings have had a huge and very positive impact in my life.
http://www.wall.org/~aron/blog/