The doctrine of the sin nature is not very popular. Even many Christians balk at the idea that all people are by nature guilty before God. Those churches which believe in the sin nature do not often teach the concept. The sin nature is also referred to as original sin and, among theologians, imputed sin. What is it?

The sin nature is the part of the person that is corrupted by sin. The sin nature is more than people committing sinful acts. The sin nature is the idea that every person is spiritually damaged. The broken part of the being produces the performance of evil deeds. 

The idea of a sin nature is found in Scriptures in the contrast between the old man and the new man. The old man is that which is natural to man and is displeasing to God. The new man is that which is supernaturally created by God in the believer with the ability and desire to live for Him. Statements like, “For as by one man’s disobedience many were made sinners” (Romans 5:19) teach that man possesses a sin nature. The truths, “There is none righteous” (Romans 3:10) and “For all have sinned” (Romans 3:23) express the universal nature of original sin. When Christians say every one is a sinner we mean that every one does things which violate the commands of God and we mean that corruption in the person moves him to break God’s laws. 

The sin nature is something more than the evil deeds done by a person. This truth is made evident in several key Biblical passages. In Ephesians 2 All the unsaved are called “the children of disobedience”. All who have not received the saving grace of God are “by nature the child of wrath.” Left to their natural state all humans are in disobedience to God and are under His wrath.

Psalm 51 says the person is tainted by sin from the very moment of conception. (Incidentally, this passage is one reason why Christians believe life begins at conception. A lump of tissue cannot be guilty of sin.) “Behold, I was shapen in iniquity; and in sin did my mother conceive me.” Sin is not just an action, a thought, an emotion, an attitude, a word or a conscious choice of a mature individual. Sin is a state of being. Sin is something bound up in the nature of the person that produces sinful actions. 

The sin nature is not the physical part of the person. Body, blood, muscle, tissue and DNA are not sinful. Jesus was a flesh and blood person who possessed all the attributes of humanity. He had a normal human body yet was without sin. Likewise, Adam and Eve possessed physical bodies and were normal human beings before they sinned. Satan is the father of sin. He is an angel, a spiritual being who lacks any physical substance. The physical part of man is not the sin nature.

The sin nature resides in the spiritual part of the man. When describing the source of evil in a man, Jesus traces it to the heart. “For from within, out of the heart of men, proceed evil . . . evil things come from within and defile the man.” (Mark 7:20-23) Man’s problem is a spiritual one. Sin erupts from the corrupted heart to affect all parts of the person. The sin nature is in the heart of man and is the spiritual corruption of the individual.