The difficulty of attempting to answer this question cannot be overstated. The Bible teaches that Adam and Eve are created “good,” that is they have an innate moral character – “created character,” as John Frame calls it. And the world at the time of Adam and Eve’s temptation was called “very good.” Adam and Eve, in other words, are not morally neutral but actually “good.” So, how, then do morally good people decide to sin? There is simply no satisfying answer this theological dilemma.
There have been a number of attempts over the years to attempt a rational explanation for this mystery. So, some have proposed the idea of libertarian free will, as a philosophical explanation of Adam’s transition from righteousness to wickedness. Libertarian free will asserts that man’s choices are free from constraint. That is he is always free to choose between two alternatives, neither our character nor God predetermine the choices we might make in any given situation. The problem, however, is that this seems to contradict the Scriptures. Scripture teaches that we are both constrained by our character (Luke 6:45) and by God (Prov. 16:9; 21:1; James 4:15).
Others suggest that man contained, within his original created nature, the “seed of imperfection.” That is, while, man was not created with sin, he contained within himself a seed that would one day grow into fully formed rebellion. So, Roman Catholic theology teaches that the differences between man’s body and soul lead to a tension of desires that have the potential to develop into sin. He was created this way and this is where sin itself originates. But all this speculation goes well beyond what the text of Scripture says. The truth is there’s just no satisfying answer to the origin of sin.
We just don’t know. We know that God allowed it to take place. We know that Satan tempted Adam and Eve. We know that Adam and Eve chose to rebel. We know that it was all part of God’s grand plan for redemption from before the foundation of the world, yet its exact out working is a mystery. We need to accept this mystery and not attempt merely to explain it away.
The reality of the Christian faith is that it is full of mystery. We believe, after all, that a man rose from the dead! We should not hide away from mystery, nor use theology to try to explain it all away. God has left this a mystery and speculation does us no good, in fact it may drive us further away from the actual revealed truths of Scripture – as is evidenced by some of the previous ideas. Embrace the mystery, let it overwhelm you and grip your mind, and let your trust of God grow. Let your dependence on His Word grow. Embrace the mystery and in so doing embrace your own intellectual limitations. Let God be God and His Word be true.
There is no satisfactory answer to the mystery of the origin of sin. There are theories and ideas. Some are okay, some are not, some are just so speculative that they lose sight of the real truths of Scripture. Get comfortable with the mystery, friends. It can serve you well not to know.