The only religion/s that will be impacted by the discovery of extraterrestrial life are going to be the Fundamentalist Christians and Orthodox Jews. There is nothing in the Bible on the subject and that will leave an open hole in their psyche..
Realizing that there might be extraterrestrial life goes against the major premise of their religion which puts man at the center of the Universe with Jesus dying for humanity due to the sins of a literal Adam and Eve. Are we to believe that Jesus died for the sins of E.T.? Has any extraterrestrial race gone through the ordeals of sin and death like their human counterpart?
Inquiring minds want to know.