I'm a Christian, I've seen a few UFOs (I've seen all kinds of crazy stuff), but I don't believe they're piloted or controlled by aliens. Hugh Ross nails this with his Residual UFO Hypothesis.
I have strong doubts about biological alien life, and even if there is some other kind of life form out there somewhere, I think the odds of it being intelligent are pretty slim, to say the least. Out of all the species that have ever existed on this planet, there has been only one intelligent species, and from an evolutionary perspective, we just got here (not that I believe in evolution, or an old Earth, for that matter).