@anthony1312002,
Different people interpret the Bible in very different ways... your particular interpretation (or mine) isn't relevant to this topic.
The question is where do these preachers get the hell fire and damnation images.The answer to that is clearly "The Bible".
The Bible has images of "weeping and gnashing of teeth", and eternal torment, and punishment so bad it is worth gouging your eyes out now on Earth to avoid it, and a lake of fire.
You can explain away each of these passages. But for the preachers who take these things literally, these passages in the Bible talk about a place of eternal torment for evildoers in a lake of fire.