From The Art and Popular Culture Encyclopedia
Sin is a term used mainly in a religious context to describe an act that violates a moral rule, or the state of having committed such a violation. Sin typically involves deliberately or purposefully harming some living organism (including human as well as other living animals or organisms) without a proper reason.
Christian views of sin
In Western Christianity, sin is viewed as a legal infraction or contract violation, and so salvation tends to be viewed in legal terms, similar to Jewish law. In Eastern Christianity, sin is viewed in terms of its effects on relationships, both among people and between people and God. The Bible portrays sin as not following God's moral guidance, based on the account of Adam and Eve in the Book of Genesis. Sin is to know God's will, but willfully choose to ignore it.