2 Corinthians 11:14-15 KJV
And no marvel; for Satan himself is transformed into an angel of light.
Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works.
Why wouldn't Satan and his ministers discourage trust in the Bible, by pretending to be aliens?
First we were told aliens are from other planets, now we are told in movies like the fourth installment of the "Indiana Jones" series, that the "Greys" are not "spacemen" but are interdimensional.
The Bible has no mention of creatures living on other planets, and even end time prophecies reveal that humanity will still be restricted to planet Earth.
There is another dimension, the spiritual dimension, and there are testimonies of malevolent beings like the so called "Grays," which disappear upon calling the name: Jesus Christ.
Keywords to search: aliens are demons