Greek religion was based on the antediluvian world and generally harmonizes with Genesis.
It was basically ancestor worship, and was practiced by many cultures, not just the Greeks.
Adam/Zeus, Eve/Hera and/or Athena, Garden of Eden/Hesperides, Serpent/Ladon, etc.
Directly mentioned in Genesis 6:4.
They didn't make this stuff up out of thin air.
It happened.