It's not an attempt to live in a fantasy. Imagine the desire to describe an inexplicable experience and resorting to the metaphors available in that time and base them all on the best technical knowledge your ancestors could pass down to you. 

If we lost this perch at the top of the tower we now enjoy how long would it be before our grandchildren (or theirs) began to believe in some inverted science mixed with a ritual of religion and movie references? : )

And to stay on topic:

Aliens traveling so far to find us might want to shop around a little before adopting the beliefs of the creatures who couldn't leave their own planet. If there is a desire to actually sell them on the ideas of Christianity you better choose the salesman wisely.

Without sounding xenophobic, all the religions are pretty much for humans only. It is more likely that if they are made of something that is intelligent enough to get here they might be more likely to start converting us to their way of thinking. Perhaps that is better that than converting us to food. 

"Save, savior": You've got to be lost in the mechanics of the non-phenomenal world to be saved and delivered into enlightenment. As our Aliens aren't defined here we don't know if they fall into the pre-existing condition that is inherent to this philosophy. 

Also, remember the image of the first god was wheat. But its difficult to imagine what wheat or the sun is thinking. It makes sense that we moved to a metaphor that was more relatable.