The Tides of God (Ace Science Fiction Special)

It's a real shame that this book is no longer in print. The premise of this story is that religious beliefs are the products of alien satelites following millenium long orbits. When these artifacts approach Earth, religion propers and civilization tends to decline. When they recede, skepticism and rationalism prevail and humanity advances. As the book opens, humans are at the apex of their most recent Enlightenment, but the satelite is, once again, approaching. Only, this time (with the aid of another species), we know it and have sent out a ship to destroy it.Although the book seems to be anti-theistic from the start, it is actually more subtle and complex than that. As the destroyer approaches the artifact, the crew comes under the sway of religious conviction, developing new theologies and schimisming into heresies at a frightening pace. But is all religion bad? Is the artifact, in fact, merely an alien device, or is it, in fact, the voice of the divine? And, if it is the voice of the divine, are we better off with it or without it? This is a complex and engrossing story. For those interested in theological fiction, I stongly recommend hunting down a copy for your personal library.