A religious overtone was blessedly absent from the first and second Alien movies... The 3rd had it as merely a plot detail. Incase you don't recall: After the Fury 101 Detainment Center was shut down a small sect (about 18 or so) of "end of the world" Christians stayed on as a custodial staff. Fine, superfluous, but fine.
The 4th however does a very weird thing. First off, there's a chapel on the ship. Now maybe there have been a few advances in the intervening centuries but the difficulty of creating a hospitable environment in space would still cause volume on a spacecraft to be at a premium. It is very unlikely that a special room (and a fairly large room) would be devoted exclusively to worship. Also... Were no other religions featured or could the "electronic bible" also display the Qur'an, etc. ? In any event it was the Bible which was on in the scene.
Another thing: Winona Ryder's (purr...) character, Call, was an android. When she entered she crossed herself. Ripley commented something to the effect of "They programmed you for that?!?"
What are the producers saying? That christianity is incredibly damn important. With both wasted space and android programming to back this up. What could be the source of this? My theory: The few remaining survivors of the Fury incident finish their time and return to civilization. They preach about their night with the "demon." They gain followers- yadda yadda yadda.
So... When Alien5 comes out it should be VERY interesting to see how they treat Ripley.
I expect, within as little as 50 years, these people who only call themselves christians will wake up to the fact that they don't have to have a label to believe in an afterlife and develope a personalized theology. I would guess about half of the Christians already do this but still call themselves Christians. If you'd like some evidence of this go visit a Christian Chat on WBS, AOL, or where ever; They argue more than any other "religion" room. (With the exception, perhaps, of the Atheist rooms... but generally it is the atheists arguing and/or deriding the Christians who wander into the room trying to save the "unbelievers")