Depends from religion tho...(btw i think that it doesn't confirm nor reject their existence.)
& i specified atheists because they don't believe in God that they can't see it so it is ridiculous to believe in aliens while there's not a single proof of their existence.
Except, there statistically is proof of extraterrestrial lifeforms. You can spend less than 10 minutes and see everything about the proof.& i specified atheists because they don't believe in God that they can't see it so it is ridiculous to believe in aliens while there's not a single proof of their existence.
If you want, you can also look up the Fermi Paradox.