The Westminster Shorter Catechism defines sin as "...any want of conformity to, or transgression of, the Law of God."
This definition provides a window into the larger framework of Presbyterian systematic theology and the still larger framework of Western thought in general. Concepts of sin, justice, law, authority are seen in terms of the abstract and absolute. What "sin" is (or justice, or law, or authority) exists as an ideological entity, defined as an eternal, unchangeable thing, which is defined by the eternal, unchangeable nature of God.
This method of breaking reality into abstracts hearkens back to Platonic and Aristotelian thought processes, which have dominated all Western thought, theology, politics and society. As the first century drew to a close, the Christian Church began to move away from its Jewish roots and ancient Near Eastern conceptual framework and embrace more and more of a Hellenistic worldview. By worldview, I do not mean a system of ethics and faith practices that is sometimes implied by the word, but I mean the basic questions that one asks in order to define reality. The very fact that soon after the first century, the Christian Church became embroiled in heated controversies over abstractions such as the nature of God, of Christ, and of humans is evidence that different questions were being asked and a different conceptual framework for reality was being used that was foreign to both the ancient Biblical authors and the Church of the New Testament era.
This is, of course, an oversimplification, but a general description nonetheless. It is how the West has come to be dominated by authority structures based upon a chain-of-command, or representational, form of government, and how Christian theology has come to be dominated by a reading of Jesus' atonement based upon Hellenistic concepts of justice. (Justice as a cosmic abstract).
I know it is hard for anyone in the West to even think beyond this framework. What is she talking about?!? So to clarify, I would like to offer an alternative based upon a theology of creation in an attempt to recapture a more Near Eastern "feel" to the Biblical narrative. I am not particularly educated in this area, so this is more of an exercise of informed imagination rather than a carefully researched thesis. I do believe that imagination is precisely what is lacking in Western thought.
What is sin?
When God created the heavens and earth, God kept saying that it was very good. I have read that "good" is an understatement. In the Hebrew language, it meant more like "Woweee!" It was an expression of intense satisfaction and delight.
The point is, that this is the first definition of goodness, so in the story so far, the creation is good. The trees, sky, stars, animals and humans are all good. The land is good. Adam and Eve did not have some abstract, cosmic concept that they knew as "good". Rather they had the green grass and the God they walked and talked with upon it.
Then came their disobedience, and their banishment from the garden. There was the first bloodshed, when God gave them animal skins to clothe themselves with. Then there was Abel's offering of the lamb, which pleased God better than Cain's offering of vegetative produce. What followed was Cain's jealousy when he let sin enter his door, and shed his brother's blood. The blood that cried out to God from the ground. The land was desecrated as a result of the desecration of Cain's heart.
We then have the great Flood, in which God repents of the creation of humanity and decides to cleanse the polluted land with a thorough washing. This washing, the Apostle Peter writes, is the type of Christian Baptism.
In the subsequent story of Israel, as told in the pages of Torah, we have the Law given, not in terms of cosmic morals, but in terms of pollution of the holy, particularly of the land and of the human body. We have, before the Mosaic law, the institution of circumcision, a bloody symbol of cutting off the unholy. There is Zipporah's pronouncement when she laid her sons' foreskins before the Angel of the Lord, saving Moses and her family from death, "Surely you are a bridegroom of blood." The taking of the promised land through genocide of the Canaanites is in terms of cleansing the land from the pollution of idolatry. And throughout all the purity codes there is this theme of being separate and holy, with the bloody sacrifices of animals shed to cleanse the land. Even the death penalty is seen in ceremonial terms. If a homicide was discovered and the perpetrator not apprehended, an animal was killed instead so the land could be cleansed.
Though Western theologians have conveniently described the Mosaic Law as consisting of both a moral and ceremonial code, in the text itself there is no such distinction. Morality is ALWAYS seen in terms of the sacramental. And it is ALWAYS seen in terms of God's particular covenant with them as the God who brought them out of slavery in Egypt. Morality is relational.
This puts a whole new perspective on Jesus' sacrifice on the cross, far different from the classic Lutheran concept of justification based on cosmic abstractions of wrongs made right in a judicial sense. It means an end to the pollution of the land. The world has been cleansed and the demands of purity met. No created thing is now unclean. Gentiles may now share Abraham's inheritance, which is bound up in Christ. Yet, according to the apostle Paul, this does not give license to sin. But sin is not simply a concept of cosmic wrongness, it is defined by that which pollutes. The Christian is cleansed through Baptism into Jesus' death, and partakes of his cleansing death through the sacrament of Eucharist. To pollute their bodies with greed, idolatry or sexual immorality is to pollute the body of Christ himself, as well as to pollute the good person that God made. The Law was given to Israel so that Israel could define, magnify and concentrate that which pollutes, which could then be dealt with by the final sacrifice of the Lamb of God, who takes away the sin of the world. And a blood that speaks a better word than the blood of Abel.
So sin, justice, and law are not abstract concepts, but things very much related to the physical creation and to our physical bodies. We are good, our bodies are good and our planet is good. We require the sacramental cleansing of Jesus' sacrifice and the presence of the Spirit to create clean hearts within us so that we will no longer walk in ways that pollute the good that God made.
If, then, I were to answer the question, "What is sin?" I would say that sin is whatever pollutes that which God made and called good.