The implication has nothing to do with intelligence. Many religions have believed that the metaphysical is intertwined with the physical world in tangible ways. A perfect example of this is the Greeks. They saw their pantheon as human shaped arbiters but also as vast forces of nature, like war or the seasons. It was a way to relate nature to ourselves, give it a human face that people can petition to for some semblance of control and order in their lives. But specifically they believed that they could speak directly to the gods and the gods could manifest on earth. In this way they did not draw hard lines between the physical and metaphysical, more like lines of who gets where and how.