When Copernicus and Galileo championed a heliocentric view of the universe, they were demonised by the Catholic authorities for fear of threatening their legitimacy. Would the discovery of alien life on other planets threaten the power and importance of modern religions in a similar way?
The existence of alien life would be a threat to religion
Alien life would challenge the legitimacy of modern religion. Religions have a clear set of beliefs, and some of them do not account for life on other planets. Some reject the possibility outright. The discovery of aliens would conflict with what these religions teach, undermining their credibility.
Religious creation stories do not account for other worlds
Religious creation stories are earth-centered and do not account for alien life. Scripture does not provide any factual knowledge about the universe we live in. The existence of aliens will prove that scripture is a relic of early superstitions.
Human religions will appear infantile after contact with advanced aliens.
Contact with superior civilizations with advanced knowledge may produce more sophisticated ideas about where religious concepts come from. We may learn more about our origins, about consciousness, and science in general. Science will turn religious ideas into natural ideas.
Alien life would threaten some but not all religions
Some religions can support the existence of extraterrestrials (or aliens) better than others. A religion’s ability to accommodate the existence of aliens would depend on how open that religion’s belief system is. If it is not, dealing with the idea will be difficult.
Religions vary in their theological flexibility with aliens
Some religions adapt very easily to new ideas in the world while others hold strict lines of thought that would struggle with new information about the world
Christianity is seen as the least compatible when it comes to religion and extraterrestrial life. Many Christians believe that life exists on other planets. If Christianity can evolve their ideologies around alien life, then other religions have the potential to evolve.