Christianity, at least as far as I have been taught it, seems to implicitly conflict with intelligent extraterrestrial life, as at the very least it would lead to questions whether the aliens also are in sin, whether Christ's sacrifice applies to them or did they have their own equivalent of Jesus, and generally how special humans are in God's grand cosmic plan.

> Religion tends to be very careful to stay in the area of not providing a testable hypothesis which means that new alien knowledge won't prove it wrong.

That's true, but until very recently, the idea of life elsewhere wasn't really considered seriously.