I disagree. From the Christian perspective there would be lots of questions to be asked, like if the aliens have original sin and if there is a duty to teach them the Gospel. These questions have already been debated in theory so I would imagine encountering an actual alien civilization would popularize them.

> From the Christian perspective there would be lots of questions to be asked, like if the aliens have original sin and if there is a duty to teach them the Gospel.

So? Why would these Christians be shaken in their belief, when there were already written considerations about the "original sin" and "Gospel" for the aliens?

I don't understand what your disagreement is.

Note: the "World" of the Bible is just a piece of the Mediterranean Sea and the piece of the Near East. Ditto for Quran. Even the whole continent (America) is not known among the people of these books, so these apparently "eternal" books don't know about that fruitful continent either.

But these faiths survived the discovery of the America. And interestingly, the more "fundamentalist" believers actually left Europe and kept their fundamentalism in America and the effects of that we feel even now.

At least the result was that the modern science (trust what is, not what's in the "eternal" books) progressed in the lands that used the "new" resources.

Sorry for not being clear. I don't think it would necessarily shake people in their beliefs, just that the discovery of alien life would have a big impact on theology, in a way that the theoretical idea that it probably exists can't. For instance right now people can debate about whether alien life would have original sin or not. Depending on your understanding of the Bible some people argue that original sin, and thus the tendency to sin and the necessity of Jesus is unique to Earth. If we meet aliens this wouldn't just be theoretical anymore, instead how the aliens acted could be used as evidence one way or the other.