Answer:
What comes in many different sizes but is always only 1 foot long?
I have a mouth on my head and eat everything.
I am a popular afterlife location to send evil people
It is greater than God more evil than the devil. The poor have it the rich need it. If you eat it you will die. What is it?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?