First, note the authority of God as He speaks to the serpent.
How boastful had the serpent been? With such unbridled confidence he had promised the woman freedom from God’s commands. In doing so did he not make himself to be God? Didn’t he give Eve the impression that his words were true while God’s Words were false? But how strange is it to see this tempter able to do nothing but listen to God cursing him? Where are his bold words now? Where is his confidence, power, and wisdom hiding? Not a word flows from his mouth as the Judge of all the earth pronounces him to be cursed. God is the Lord, He will not give His glory to another, and no one is His equal. When God speaks, no one speaks back. Sure Satan may be wise, wiser than us, and his wisdom may overwhelm us, but his wisdom is a microscopic drop of water compared to ocean of God’s mighty wisdom. Here we see that Satan the creature is no match for our Creator. For Satan this is the most humiliating moment of his entire existence, “for he hears his doom uttered with infallible authority.” (E.J. Young)
Second, Genesis 3:15 embraces all that is noble and glorious that is to be found in the Scriptures.
Adam and Eve plunged themselves into death and darkness by believing the serpent and eating the fruit. They as our first parents therefore plunged the whole of mankind into death and darkness from such evil. It is now natural and normal for us to hide from God, to believe lies, and to be against our Creator. We now call good evil and evil good. All of mankind now finds himself in need of life, light, and rescue, and in this verse God promises that very thing. There is no enmity or hatred between the serpent and mankind, but God will place it there. Between the offspring of the serpent and the offspring of the woman, enmity (hatred) will exist. Adam had seen the serpent as his friend and God as his enemy. Adam was willing to listen to his words and ignore God’s. Adam must learn the opposite – that God is his friend and His Word alone is to be trusted. In order for this to take place within Adam a complete reversal of heart must occur. He must learn the serpent was merely pretending to be his friend and is his largest enemy in life. Adam must be at enmity with the serpent and because God said, “I will place enmity” between these two parties for all time we see that God takes the initiative to save His own people through His triumphant sovereign grace. God must do this if man is to be redeemed. If God does not place enmity between them there is no hope.
Third, note the Person in view.
“…He shall bruise your head, and you shall bruise His heel.” Just as the man and woman were to be at enmity with the serpent so also will her seed and the serpents seed be at enemies. What does ‘the woman’s seed’ mean? Is it referring to one individual or is it referring to all those who descend from Eve? In the early Christian Church most believed there is here a specific reference to the ‘Seed’ of the woman, Jesus Christ. It is interesting to note that as the centuries progressed, and especially after the enlightenment many began to move away from that view saying there cannot possibly be such a reference of Jesus Christ in so early an OT book. But in the OT there is a remarkable progression of God’s revelation of the truth concerning the Messiah to come. As you move forward in OT progression the prophecies concerning the Christ reveal more and more about who He will be and what He will do.