The theological difficulties posed by the possibility of advanced alien beings are less acute for Judaism and Islam. Muslims, at least, are prepared for ETI: the Koran states explicitly, "And among His Signs is the creation of the heavens and the earth, and the living creatures that He has scattered through them." Nevertheless, both religions stress the specialness of human beings—and, indeed, of specific, well-defined groups who have been received into the faith. Could an alien become a Jew or a Muslim? Does the concept even make sense? Among the major religious communities, Buddhists and Hindus would seem to be the least threatened by the prospect of advanced aliens, owing to their pluralistic concept of God and their traditionally much grander vision of the cosmos.
Among the world's minority religions, some would positively welcome the discovery of intelligent aliens. The Raëlians, a Canada-based cult recently propelled to fame by its claim to have cloned a human being, believe that the cult's leader, Raël, a French former journalist originally named Claude Vorilhon, received revelations from aliens who briefly transported him inside a flying saucer in 1973. Other fringe religious organizations with an extraterrestrial message include the ill-fated Heaven's Gate cult and many UFO groups. Their adherents share a belief that aliens are located further up not only the evolutionary ladder but also the spiritual ladder, and can therefore help us draw closer to God and salvation. It is easy to dismiss such beliefs as insignificant to serious theological debate, but if evidence for alien beings were suddenly to appear, these cults might achieve overnight prominence while established religions floundered in doctrinal bewilderment.
Ironically, SETI is often accused of being a quasi-religious quest. But Jill Tarter, the director of the SETI Institute's Center for SETI Research, in Mountain View, California, has no truck with religion and is contemptuous of the theological gymnastics with which religious scholars accommodate the possibility of extraterrestrials. "God is our own invention," she has written. "If we're going to survive or turn into a long-lived technological civilization, organized religion needs to be outgrown. If we get a message [from an alien civilization] and it's secular in nature, I think that says that they have no organized religion—that they've outgrown it." Tarter's dismissal is rather naive, however. Though many religious movements have come and gone throughout history, some sort of spirituality seems to be part of human nature. Even atheistic scientists profess to experience what Albert Einstein called a "cosmic religious feeling" when contemplating the awesome majesty of the universe.
Would advanced alien beings share this spiritual dimension, even though they might long ago have "outgrown" established religion? Steven Dick, a science historian at the U.S. Naval Observatory, believes they would. Dick is an expert on the history of speculation about extraterrestrial life, and he suggests that mankind's spirituality would be greatly expanded and enriched by contact with an alien civilization. However, he envisages that our present concept of God would probably require a wholesale transformation. Dick has outlined what he calls a new "cosmotheology," in which human spirituality is placed in a full cosmological and astrobiological context. "As we learn more about our place in the universe," he has written, "and as we physically move away from our home planet, our cosmic consciousness will only increase." Dick proposes abandoning the transcendent God of monotheistic religion in favor of what he calls a "natural God"—a superbeing located within the universe and within nature. "With due respect for present religious traditions whose history stretches back nearly four millennia," he suggests, "the natural God of cosmic evolution and the biological universe, not the supernatural God of the ancient Near East, may be the God of the next millennium."