why not?
I think it's pretty narrow-minded and self-righteous to think we're not alone in the universe. No matter what particular creation account you subscribe to, I don't think you can, after having looked into the mathematical probabilities for it, logically deny that there is a distince possibility of their being other life out there. Any of Carl Sagan's books are great reading on this subject (particularly Cosmos, which ought to be required reading in 8th grade science classes, at least so says I)...
Though I've never encountered one myself (knowingly, anyway), I can only hope that if we ever do run into some, they're not as cocksure, paranoid and aggressive as we homo sapiens tend to be...