Adam and Eve, lived in Heaven in total innocence.
Then they ate the fruit from the forbidden tree of knowledge.
By doing so, they chose their free will.
The free will is the personal thought, the Ego mind.
Hence, the Great Illusion in human experiences began.
If we let go of the Ego mind, the personal thought,
we let in the Divine Thought, and we are in Heaven again.
It's this simple.
Death is the death of Ego Mind.
We die either by leaving the physical plane or giving up the Ego Mind.
An enlightened one has already died once.
Heaven is not a place, it's a state of consciousness.
An Enlightened mind is in union with the Divine Mind.