this is an idea I've long considered and I intend to think in greater earnest about it after having read this essay. what would be the consequence theologically of our finding life elsewhere? not necessarily nasty or enlightened life and not even intelligent--by which we almost always mean "more intelligent than we are"--life, but life of a sort we would recognize?
this would have a tremendous impact as most faiths assume this planet is alone in the universe as a site for god's or nature's or ultimate reality's experimentation. it's a science fiction topic ripe with possibilities and I almost never see it handled in novels or movies. almost invariably extraterrestrial life is handled almost like we handle new neighbors we hadn't realized were building over the hill: surprise and then reaction to their behavior that has an impact on us.
what if the raelians and scientologists and ufo cults are right, not in their particulars, but in their generality that we share the universe with other independently developed beings? would faiths adapt, accepting these unknowns as co-existers? would the unknown itself become the new god or some aspect of a new god? or would most religions retreat into isolationism, claiming that there really isn't any other life or that it isn't important or it's a development of the adversary (as some have done with fossils)?