Extraterrestrial civilizations. What is your opinion?

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Why not? Anything is possible. And they probably all exist.
But I hope there won't be any like in Wells' "The War of the Worlds."
Although, anything is possible.

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Berserk;81946

I believe that aliens don't exist. The evidence is simple: for believers, it is written that Adam and Eve were the first people. No one else was created. Dr. Kent Hovind supports this version. For atheists, I will use two arguments:

1) (from Ganymede) - I haven't seen it, so I don't know.
2) Most UFOs have been explained and were either objects, phenomena in the atmosphere, or meteors. In general, thousands of explained phenomena confirm that UFOs do not exist.

I have one small question: why are you so sure that the Bible is correct? They could have written anything in it, and when talking about extraterrestrial civilizations, you simply cannot rely on the Bible.
After all, it is quite possible that God created others later or earlier, and they were banished earlier (or later).
Regarding the first point:
Not seeing something doesn't mean it doesn't exist; there is only a probability that we are alone.
Regarding the second point:
Well, it's not impossible that they haven't visited? After all, there is only a probability that they don't exist. They may not have been interested in people, because, as someone said, we are not yet at the stage of development to be of interest to them, or for some other reason.

Ничего нет только у мёртвого - у живого есть хотя бы жизнь...