Question #555: I need urgent help about a dream about a Demon

Probably doesn't mean anything. Unless you are actively against the JoS, you wont have a negative experience with the Gods. Also telepathic communication goes beyond language, its thoughts and intent that you interpret and decipher, so the Demon could speak any language, but you would understand it in your native tongue for example.

Yesterday I was studying about the Demons to ask them for help with some of my questions and that night I dreamed that a Demon was in the body of the little son (as if he had possessed the boy) of a neighbor of mine (I don't know if it's important but I I've already had some arguments with her because her son cries and screams all day, and it's very annoying - he screams and cries from the time he wakes up until around 11 pm).

And suddenly this Demon started talking in a language I didn't understand (but the impression it gave was that the Demon was angry) and then they started banging on my apartment door as if they were punching and I woke up.

Can someone help me?

The Demons do not give negative experiences. If this did mean anything at all it could be your subconscious revealing your own fears about reaching out to the Gods and the astral, or even enemy interference trying to frighten you.