Sorry to spew this all over the intarwebs, but I have nowhere to write.
Why are so many animes obsessed with science and religion? And more to the point, why are the Japanese so gung-ho happy to intermingle them, to write up stories of machine gods and biological angels?
I think it is because, to many Japanese, science
is religion, or more accurately, technology is religion. And I don't mean this in a joking fashion, as in, they bow down and worship their digital cameras. Religion isn't about worship, not really. In my mind, religion is about an investment of purpose.
Aum Shinrikyo, the famous cult that attacked Tokyo subways, wore hats with electrodes on them for spiritual cleansing. Likewise, their sacred substance was water through which electric currents had been running. Granted, this is not unique to Japanese dingbat religions (Scientology is a brilliant example too) but it's become very popular in Japan - perhaps for a reason.
Under the last Emperor, I think there were few Japanese who felt they lacked a sense of purpose. Most of them were amazingly driven, and felt that the Japanese Empire needed them for a great and important task. Then the Emperor declared that he wasn't divine (and many heard this message over the radio); the Japanese were left without a divine imperative, but with a massive, industrialized, impersonal machine that was Japan.
So they rebuilt their country, and were left with a speedy, efficient, scientific society. But they lacked a unified purpose; technology only provides a means, not an end. It's only natural that the means by which they rose from the ashes should be an object of much respect - technology is everywhere in Japan, but few understand it. So perhaps, when they write fiction about biological angels, it rises in popularity because some sort of desperate hope that perhaps one day, the scientists in their laboratories will discover God.
Or perhaps I'm overanalyzing. Nonetheless, it's an interesting theory, so desu ne?