Which religion will have the toughest time reconciling aliens with its beliefs?

The ones that have decided that we humans are the sole focus of God’s attention. The religions that see the world through that viewpoint tend to be some of the Christian evangelicals. The Eastern Orthodox Church, a branch of Catholicism, also has that view.

Did Jesus Save the Klingons? – Scientific American. Meanwhile, here we have an astronomer, David Weintraub of Vanderbilt, who has written a whole book about “religion and extraterrestrials” without bothering to learn anything at all about Christianity. He’s just making up shit as he goes along, but it’s hard to do better than “The Eastern Orthodox Church, a branch of Catholicism.”