What makes sin sin?
No, forgive the circularity, but murder is wrong because it is wrong, just as God exists because--well, because He exists. Theologians have spent a great deal of time rationalizing the existence of God, yet it should be obvious when we look at God's creation that He exists. Likewise, philosophers, for their part, have spent a great deal of time rationalizing the existence of the conscience. Perhaps both need to spend more time in their Bibles for their answers.
The idea of a social contract is a convenient way to explain human morality without having to acknowledge the Creator of our morals. The idea is suggested that humans generally refrain from murdering one another because they have a natural desire not to be murdered--a kind of amoralist approach to the Golden Rule. But this is more of a rationale for why humans might choose to behave morally, not a rationale for where the morality comes from in the first place. For instance, it is universally wrong to murder a man, even if the murderer is on a remote island where he has no fear of being murdered himself. Murder is wrong in all cultures and in all circumstances, and there is no way to explain this except by acknowledging the Creator of our morality.
What makes sin sin, then, is not the written words of the Bible. That is how we learn about the subject of sin, of course. That is how we learn that it separates us from God, and that we have a way to end that separation through Christ. But the fact that a sinful behavior or attitude is listed in the Bible is not what makes it a sin. In fact, sin should simply be obvious to us:
- Galatians 5:19-21 - The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God. (NIV)
The divine origin of our morality is comparable to the divine the origin of wisdom. Solomon knew something about wisdom. He wrote a book about it that we call Proverbs, noting that wisdom comes from God:
- Proverbs 2:6 - For the LORD gives wisdom; From His mouth come knowledge and understanding; (NKJV)
So what? What is useful in thinking about sin in the proper way? The primary benefit is that it frees us from the letter of the written code:
- Colossians 2:14 - ...having wiped out the handwriting of requirements that was against us, which was contrary to us. And He has taken it out of the way, having nailed it to the cross. (NKJV)
Galatians 3:10-14 - For as many as are of the works of the law are under the curse; for it is written, "Cursed is everyone who does not continue in all things which are written in the book of the law, to do them." But that no one is justified by the law in the sight of God is evident, for "the just shall live by faith." Yet the law is not of faith, but "the man who does them shall live by them."
Christ has redeemed us from the curse of the law, having become a curse for us (for it is written, "Cursed is everyone who hangs on a tree"), that the blessing of Abraham might come upon the Gentiles in Christ Jesus, that we might receive the promise of the Spirit through faith. (NKJV)
- Galatians 6:2 - Bear one another's burdens, and so fulfill the law of Christ. (NKJV)
Jeremiah 31:33 - But this is the covenant that I will make with the house of Israel after those days, says the LORD: I will put My law in their minds, and write it on their hearts; and I will be their God, and they shall be My people. (NKJV)