The Greek god associated with the harvest and fertility is Demeter, the goddess of agriculture. She symbolizes the cycle of life and seasons, particularly the growth and harvest of grain. Demeter's relationship with her daughter, Persephone, illustrates the duality of life and death, as Persephone's annual descent into the underworld signifies the winter months during Demeter's grieving. This myth reveals profound themes of renewal and the significance of the agricultural cycle in ancient Greek culture.