-The Avos were bigger then Chanoch and Eliahu, why didn’t  they merit to become angels after their death?
-Know that big tzadikim (holy sages) are bigger then angels.
-Their souls come from a higher source and they reach much 
higher levels.
-They become channels for all the worlds energy, while 
angels just distribute the energy.
-The Avos reached these levels. To become angles would 
have actually lowered them from their current state.
(Medrish Talpyot, branch of Avos)