Have the powerful beings ever admitted to being fearful?

Have the really powerful beings, such as Celestials, Galactus, Phoenix Force, Lucifer, Michael, Thanos with IG, Mr. Mxy, Eternity, etc., ever admitted to being afraid?

Thanks for your answer, but I meant beings that are much more powerful than Superman.

@trickyman86: He's not that powerful

They have admitted that there are beings much more powerful than themselve. They say it with respect, not fear though