Where the "Science-Religion" Dichotomy Came From
Many theistic evolutionists seem to think that science explains nature, while religion has nothing whatsoever to do with nature. The historian of science Frederick Gregory in his book, Nature Lost? Natural Science and the German Theological Traditions of the Nineteenth Century (Harvard University Press, 1992), explored the issue in nineteenth-century German theology and showed the heavy influence of Kantian philosophy on this development. Kant posited a distinction between the phenomenal realm (i.e., science, determinism, things-as-we-perceive-them) and the noumenal realm (i.e., God, free will, immortality, and things-in-themselves). This works itself out in many ways in Western intellectual history, giving rise to various dichotomies: science-religion, fact-value, knowledge-faith, objectivity-subjectivity, etc.
Most theistic evolutionists use this dichotomy to try to insulate religion from scientific and historical critiques. Of course, it also removes religion from the realm of reality, transporting it into the realm of the purely subjective. For an extensive discussion of how this dichotomy works itself out in Western culture, read Nancy Pearcey's most recent book, Saving Leonardo.