Hi
There's an excellent book on this, "Alien Intrusion: UFOs and the Evolution Connection" by Gary Bates. In it he looks at UFOs, alien abductions etc. He shows how we have to take this seriously given the number of people who report such experiences, but does so in the context of what the Bible teaches. After showing that it cannot be real aliens, he looks at scriptural evidence and shows that these experiences have a lot in common with demonic activity as reported in the Bible - down to the most common names aliens have being linked with pagan gods in ancient times, and the alien's message which is opposed to Jesus. He also documents how some people have stopped "abductions" dead in their tracks - by calling on Jesus for help.