A lot of well-meaning people want to accept the successes of science as well as the comforts of religion. There is some obvious tension here, since religions typically seem to make strong claims about the way the world works, and these claims tend to be incompatible with the lessons of science. In the face of this tension, a common strategy is to declare that science and religion simply exist in separate spheres, and cannot in principle come into conflict. This is the move made by Jesse at Pandagon, not to mention Stephen Jay Gould in Rocks of Ages. Gould even invented a clunky acronym to encompass this position: the Principle of NOMA, or Non-Overlapping Magisteria.
The problem with this position is that it is manifestly incorrect. Or at least, to make it correct, one needs to distort the definition of “religion” beyond recognition. Religion has a number of components: ethical ones, spiritual ones, social ones. But without a doubt it has a cosmological component — making certain definite claims about the nature of reality. These claims differ from religion to religion, but typically involve the existence of supernatural forces, some notion of an afterlife, a creation myth, and so on. All of these topics fall squarely under the scope of scientific investigation (and the science story never agrees with the religion story). How to wriggle out of this? By limiting “religion” to some very thin ideas about ethics and spirituality. Gould makes it through half of his book before he comes clean and gives a definition of what he means by religion, at which point we discover it is what most of us would call “moral philosophy.” At which point, why call it “religion” at all? Does anyone believe that the folks who invented these religions felt that they had nothing to say about the deep workings of the universe? That’s just a later interpretation, designed to cover up the dramatic failure of scripture to tell us anything correct about how the world really works. Why not just admit that the lessons we learn by reading the Bible are on precisely the same footing as those we learn from reading Homer or Shakespeare, and enjoy them for the messy fallible things they are, rather than insisting on some special metaphysical status?
Of course you can be both religious and scientific, plenty of people are. But if so, you should face up to those bits of both which tend to disagree. Pretending that they don’t exist is a cop-out.