Hi, Soul man.
The answer to your question is simple, ... but complicated. Gen. 3:15 is the very beginning of a theme that runs all the way throughout the entire Bible from Genesis to Revelation. You will hear many say that one seed is Jesus and the other is something else, but that just doesn't align with scripture at all.
All throughout scripture there is this echoing theme of two very different types of people. The first repeat of this is Gen. 25:23 referring to the twin birth of Jacob and Esau. (Look closely at the birth and characters of Cain and Abel)
(Gen. 25:23) "And the Lord said unto her, Two nations are in thy womb, and two manner of people shall be separated from thy bowels; ..."
Twins by birth, but very different. Look how strange Esau appeared when born. He was red and covered with hair, while Jacob looked unremarkably normal.
(Gen. 25:25) "And the first (Esau) came out red, all over like an hairy garment;..."
Why did God love Jacob, but Hate Esau?
(Malachi 1:2-3) "... Was not Esau Jacob's brother? saith the Lord: yet I have loved Jacob, And I hated Esau ..." (Romans 9:13)
It is clear from scripture that God's displeasure with him was due to something inherent (pre-birth) since Isaac, their father, adored Esau while Jacob was a bit of a trouble maker. God is a spirit (John 4:24) so there was something spiritually...unsound...about Esau.
There are other twin births like Pharez and Zerah (Gen. 38:27), and if you look closely at (Gen. 4:2) you will see that Eve gave birth to Abel immediately after Cain making them twins as well. Simply put, one seed is of the serpent and the other is of Adam and thus God.
Many violently reject this, but it says quite plainly right there in the verse, "I will put enmity (hostility) between your seed (the serpent's) and her seed (Eve's/Adam's/God's)(Gen. 3:15).
Just HOW that seed got into Eve is the main sticking point for most, but let's be honest. Does it really matter to the main idea of this concept? Not really. It's senseless to throw out an entire concept in scripture over one small point. If it's easier to accept, call it a spiritual event; somehow the seed of Adam and the seed of the serpent got inside Eve in a spiritual way. How 'bout that? Regardless, the theme is clearly strewn all throughout scripture.
The Wheat and the Tares
(Matthew 13:24-30, 37-43)
The Sheep and the Goats
(Matthew 25:32-46)
The Figs and the Olives
(James 3:12)
The Children of God and those of the devil
(1 John 3:10)
The Elect and the lost
(2 Timothy 1:9)
And you can also trace the concept of those who were created for destruction all through scripture.
(Romans 9:22) "What if God, willing to show His wrath, and to make His power known, endured with much long-suffering the vessels of wrath fitted to destruction:"
(Proverbs 16:4) "The Lord has made ... the wicked for the day of trouble."
(Habakkuk 1:12)"O Lord, thou hast ordained them for judgment; ... thou hast established (created) them for correction."
(1 Peter 2:8) "... to them which stumble at the Word, being disobedient: whereunto also they were appointed."
(2 Peter 2:12) "... these, as natural brute beasts, made to be taken and destroyed, speak evil of the things that they understand not; and shall utterly perish in their own corruption;"
(Jude 4) "... there are certain men ... who were before of old (since the beginning) ordained to this condemnation, ..."
So, there's a start for ya. As you say, study and research scripture as much as you possibly can. You will never regret a moment spent searching and seeking in God's Word - likely just the opposite.
God bless.
