The Bible uses many terms to describe the nature of sin: ignorance (Eph. 4:18), error (Mk. 12:24-27), impurity, idolatry (Gal. 5:19-20), trespass (Rom. 5:15), etc. Sin's essence is placing something else in God's place. It is anything that falls short of His glory and perfection. Sin is disobedience.