Curse: “To the Serpent”
The curse on the serpent, like those on man and woman, came in two parts.  First, “Cursed are you above all the livestock” (v. 14), and “I will put enmity between you and the woman” (v. 15).
In the first part of this curse, God promises that the ultimate victory will be the Lord’s. The enemy of man will be condemned to eat dust all of his days. As Donald Barnhouse explains,
“To eat dust is to know defeat, and that is God’s prophetic judgment upon the enemy…. There will be continuous aspiration, but never any attainment” (Genesis: A Devotional Exposition [Zondervan], p. 22).
God spoke to the serpent: “You will crawl on your belly and you will eat dust all the days of your life” (v. 14). The outcome is certain, the enemy has been defeated.
The second part of the curse to the serpent, to most scholars, represents the ultimate victory over sin through the death and resurrection of Jesus Christ. I believe it is important to break down verse 15 to better understand it.
Verse 15 begins with the relationship between the serpent and the woman: “And I will put enmity between you and the woman, and between your offspring and hers.” What is enmity? This is one of those words many read but not all understand. My study indicates that this Biblical use of the word enmity is indicative of “a mutual and deep rooted feeling of hatred and hostility.” Hatred!  These are strong words here. There is no hope of reconciliation for the serpent. And when we add the offspring of the serpent and the offspring of the woman into the discussion, we realize that this will be for all time. It is not just in the garden. This is not just Eve.  The relationship between the serpent and the woman is a lasting, mutually hostile relationship.
The second half of verse 15 offers hope that there is an end in sight: “He will crush your head, and you will strike his heel.” Referring back to the offspring of the woman, “He” (most theologians agree) is the Son of God, born of a woman. Speaking to the serpent, He shall bruise you on the head in a crushing blow. God, through Jesus Christ His Son, will deliver complete destruction to the enemy. In that day the evil one will be defeated. The curse to the serpent will be fulfilled.
The final line of verse 15 describes the act of victory: “And you will strike his heel.” Jesus, the Son of God, offspring of the woman, will suffer and die a sinner’s death on the cross. This is not, however, the end of the story. Through the glorious resurrection, Jesus lives again! His wound was on his heel, and was temporary. The ultimate victory goes to the King of kings and Lord of lords!