When the woman saw that the tree was good for food (Genesis 3:6)
Where was Adam when the snake was tempting Eve? Where was he when she picked the fruit? Where was he when she began to eat of it? The sad answer is that he was standing by watching as his wife succumbed to the deception of the serpent. Therefore, the greater sin fell upon Adam. Eve was deceived; Adam sinned willfully. The scriptures are clear, "Adam was not deceived, but the woman being deceived, fell into transgression." What would have happened if Adam would have taken a rake and killed the snake? How would God have responded if Adam intervened even at the last moment to stop Eve from eating? What might have happened, even after Eve ate the fruit, if Adam would not have eaten and prayed for his wife? We do not know for sure, but we can wonder. Maybe, just maybe, God would have granted repentance. Maybe we would still be in the garden.