The divine economy may not tolerate deficit spending, wickedness, sin, error and imperfection through eternity. God is perfect and that which He created that have free will aren't. They need be adopted by Christ's atoning sacrifice so God does not see the sinful character.
Maybe God creates a virtual box for the saved to allow them to exist eternally with Christ's help. For the lost that reject Jesus and go their own way a Universe without God for eternity would become a hell I would guess. Spirits might cohere as the Universe cycles to gravitational collapse and infinite heat in a singularity. Scientists say that below absolute zero the temperature probably is infinitely high. If the Universe with entropy disperses to heat death a phase change may flip it to infinitely hot. Hell for those godless spirits malingering for eternity within the infernal realm.
