The phenomenon of UFO's and alien life, in the opinion of many Athonite fathers as well as other spiritual persons, is that all of these are demonic manifestations and belong to the signs that Christ foretold, when He was asked about the end of the world, "and great signs shall there be from heaven" (Luke 21:11). It is a topic usually spoken of in the context of the End Times. Below are a few specific quotes on the topic:
Elder Thaddeus of Vitovnica
Question from Professor Z.S.: What can you tell us about the cosmos beyond the earth? Can you tell us whether aliens exist?
Response of Elder Thaddeus: Yes, there are... Only they are the energy of thoughts. It is not material energy as we humans know it. Such creatures as we humans do not exist in the universe. Why? Because only the human race is blessed to "fill" God's earth as the Lord said. "And God blessed them, saying: increase and multiply and fill the earth" (Genesis 1:28).
