It's not just the religions of the Book which use that metaphor. The whole Buddhism, the whole Hinduism (to the extent that such a thing does exist) - they all say: man = spirit, woman = matter.
Yeah, well I guess it's a hard thing to really pin down, but I have always interpreted the less male dominated religions as seeing the female as the spiritual or guiding or creative force and the male as being the force which works to bring that creative energy into solid form.
It's not just the religions of the Book which use that metaphor. The whole Buddhism, the whole Hinduism (to the extent that such a thing does exist) - they all say: man = spirit, woman = matter.