In Buddhist thought, Hells, of various types, do exist. One is put there for a period of time, which can be eons, but is not for eternity. However long it takes the consciousness that allows for those Hells to be, to change, so that a new consciousness can emerge, is the period of time one spends in such a Hell.
Where there is a forgiving God, who is merciful, surely, Hell is not eternal, but temporary, for all is of God’s creation. Why would God, condemn a part of itself to Hell, forever and ever?