Study the Word. It may not say what you’ve heard.
“Work out your own salvation with fear and trembling.”
Just as the English word “bad” can mean the opposite of bad, the Hebrew idiom “fear and trembling” can mean something other than the obvious.
Read: “Fear, Trembling, Salvation”
“Sinners will burn in hell forever.”
The devil and his angels might burn forever. However, I don’t think condemned humans will do the same.