We can only speculate about what would have been if Eve and Adam had kept the fast which God gave them in Paradise. Maintaining the fast – not eating from The Tree – would have defeated Satan’s plan.
As long as they kept that fast, Satan was bound and curtailed. Rejecting the fast to follow their own will freed Satan from all constraint and bound our hapless first ancestors over to slavery to sin and death.
St. John Chrysostom’s words remind us of the importance of fasting as we continue our Lenten sojourn:
“He (Satan) appears to be bound by fetters, and truly so, when he sees fasting joined together with her inseparable sister, prayer. And for this reason Christ says: ‘This kind is never cast out except by prayer and fasting.’ Therefore, since fasting expels the hostile foes of our salvation in this manner and is so terrible to the enemies of our life, we must cherish and embrace her, not dread her. We must be afraid of drunkenness and gluttony, not of fasting. For she binds our hands behind our backs and surrenders us as slaves and captives to the tyranny of the passions, which resemble a most dangerous mistress.
Fasting, however, who finds us slaves and prisoners, loosens the bonds and delivers us from the tyranny; she restores us to our former freedom. Since, however, He combats even our enemies, delivers us from tyranny, and restores us to our former freedom, what other greater proof do you seek of His love toward our race?” (St. John Chrysostom on Repentance and Almsgiving, pgs. 56-57)