Many Bible teachers will say that “God’s law written on our hearts” simply means “the Holy Spirit dwelling in us.” And many Bible teachers will say there was nothing magical about the fruit that Adam and Eve ate from the tree of the knowledge of good and evil. I think many Bible teachers may be wrong.
Here’s an idea I’m pondering that seems to make a lot of sense:
God created humans with consciences so they would know right from wrong. The first two humans had consciences but they knew very little of God’s moral law.
Adam and Eve disobeyed God by eating from the tree of the knowledge of good and evil. This was a magical tree (like the tree of life) and it gave them knowledge they did not previously have. When they ate the fruit from this tree, their eyes were opened and they knew God’s law. They immediately saw that they were naked and they were ashamed. They weren’t ashamed of the sight of their bodies, and they weren’t ashamed of their partners seeing their bodies, but the knowledge that naked bodies could be used in the future in shameful ways caused them to feel shame. They knew their nakedness would result in sin if not covered up. (There are numerous references in the law forbidding the uncovering of a relative’s nakedness.)
Adam and Eve would have passed their new-found knowledge on to the next generation, and they to the next generation, and so on (Genesis 26:5, Exodus 16:28). However, since humans found that God’s law brought conviction of sin, they ignored it or replaced it with their “morality” and failed to pass it on in its entirety. This is why God wrote the law on stone tablets and had Moses record the law for the Hebrews after bringing them out of Egypt (approximately 2500 years after revealing it to the first humans in the garden).
Pagans, from nations that had all but forgotten the law which was given to their ancient forefathers, still had consciences and basic knowledge of right and wrong. Romans 2:15 says although they did not have the law, they still had the “work of the law” written on their hearts as well as their consciences so on the day of judgment, they would be judged according to how they lived up to the knowledge they had.
Around 600 years before Christ, Jeremiah prophesied of a time when when God’s law would not just be known but would be obeyed. He said a new covenant would be made between God and men in which He would write his law on the hearts of his people. At that time he said people would know God but not because they were taught about him by a friend or neighbor. And he also said that at that time their sins would be forgiven.
We now live in this new covenant. Through the word of God who became flesh (and not through another set of stone tablets), we have come to know God in the person of Jesus. We have learned the law of God; it has once again been written on the hearts of men through the teaching of Jesus and his apostles (Acts 17:30).
Today, just as in the past (Psalm 40:8, Isaiah 51:7), those who know God’s moral law and live with a clear conscience in regards to this knowledge have the law written on their hearts.
In the Old Testament, Adam and Eve received the law after eating the forbidden fruit; later, the Hebrew people received the law again through the prophet Moses; but in the new–and superior–covenant, we have received the law from God in the flesh. And we have not only received the law, which makes us conscience of our sins, but when we place our faith in God, our sins will now be forgiven!