What Am I Riddles

Question: I cannot be seen, cannot be felt,
Cannot be heard, cannot be smelt.
I lie behind stars and under hills,
And empty holes I fill.
I come first and follow after,
End life, kill laughter.

What am I?

Question: Not chest or box is now discussed. Money can be held in it, but just as we test its metal, within it there is rust.

[What is it?]

Question: You can call me a home, but I have no doors.
Someone lives inside me, but leaves when there's no more.

What am I?

Question: I have no heart Yet I can live Even if I have fallen Fires are my enemy You are my enemy

Question: im fast and slow I go everywhere you go yet you cannot see me im in tree's in the sky in plants and in your body pretty much you need me to survive what am I?