Where and how could God reclaim the son and daughter who had been taken by Satan? There was no way without a price. So the history of separation began in order to determine the question of ownership between God and Satan. This was what Christianity calls the history of sacrifice.

Satan claimed ownership because of his blood relationship with Adam and Eve. In order to reclaim His children, God suggested the condition of sacrifice. This is the explanation of the history of God's providence to restore his son and daughter. God has continued this providence until today.

In other words, because of the human fall, the history of sacrifice began. Even though they belonged to Satan because of the fall, from the point of view of the principle, Adam and Eve originally belonged to God, as His son and daughter. So God, as the Creator, took the position of parent and owner. Satan knew God was the Creator of man, so he could not claim exclusive ownership. God had no choice but to carry out the providence of sacrifice and separation. So He saw the first son on Satan's side and the second son on God's side, and had them make offerings to establish the condition for determining ownership.

That's why God saw Cain on Satan's side and the second son, Abel, on God's side. According to the order of Eve's fallen acts, Cain represented the fruit of her wholly unprincipled relationship with Satan, and Abel represented the fruit of her more principled relationship with Adam.