There are several passages of Scripture that help us to define sin. Sin is a transgression of the law. “Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law” (1 John 3:4). To transgress means to go beyond, to overstep the boundaries, to exceed the limits imposed upon us by God. Some look at Romans 3:20 to help, “For all have sinned and come short of the glory of God.” Sin or being sinful is then missing the mark or our shortcomings before God.
Those definitions are fine, but I want to look at something else a little deeper. What is sin? Or, “Why is something sinful?” Some describe God as a cosmic killjoy. Viewing God simply as one who declares something sinful arbitrarily. Something like Roman Emperor Caligula (AD37 – AD41), who would make rules, write them on a little board and posted high on pillars so no one could see them. Caligula would then punish lawbreakers who were unaware.
God is not like that. We must always remember that God’s laws are given to us for our own good. The One who made us knows what will bring us true happiness, but in spite of this truth, people would rather follow their own will. First John 5:1-4 reminds us that God’s commands are filled with love, life, and are not “burdensome.”
C.S. Lewis wrote in, Mere Christianity,
“God made us: invented us as a man invents an engine. A car is made to run on petrol, and it would not run properly on anything else. Now God designed the human machine to run on Himself. He Himself is the fuel our spirits were designed to burn, or the food our spirits were designed to feed on. There is no other. That is why it is just no good asking God to make us happy in our own way without bothering about religion. God cannot give us a happiness and peace apart from Himself, because it is not there. There is no such thing.”
We were made in rhythm with creation. God declared a threatful warning in Genesis 2:17, “of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.” Sin has consequences and as the first part of Romans 6:23 reads, “For the wages of sin is death.”
It is easy to see that what God deems sin are those things which try to diminish the glory of God and destroy the life of man. Sin devalues human dignity. Disobedience is celebrated over obedience. Sin is the corruption and ruination of humanity. Sin is that which eventually deals out death.
Lewis, C. S. (2009-05-28). Mere Christianity (C.S. Lewis Signature Classics) (p. 50). Harper Collins, Inc. Kindle Edition.