I believe in the possibility of UFOs, but I don't believe they are extraterrestial craft...extra-dimensional, perhaps. There have been a bunch of Von Dehnegen(sp?)-like speculations over the years that the biblical accounts of angelic visitations were really "ancient astronaunts" from other worlds. To the contray, I think it highly likely that sitings of "extraterrestial craft" today could actually be angelic visitations.
Fascinating theory....I'll have to learn more about "ancient astronauts" and angelic visitations.