Answer:
I'm the start of eternity and the end of space. There are two of me in heaven and one in hell.
Rotten trees and Jack-O-Lanterns have this characteristic in common.
You speak this when you are being sincere.
Used to keep prisoners silent and to make temporary repairs on cars.
A setting that proved to be deadly for Abraham Lincoln.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?