"It is impossible to deny the existence of sin, when the whole world is in conflict between good and evil. If sin were not a fact, there would be no crime; we would not need jails or prisons. We would need no locks on our doors, or vaults for our valuables. To some, sin is being indiscreet; or it is a weakness of the flesh. To others, it is the absence of good. To the so-called scholar, sin is ignorance; and to the evolutionist, it is the nature of the beast. The latest theory is that sin is a disease to be treated by science, because man is not a sinner - he is only sick. To others, sin is a form of selfishness, but God declares that:
1) Sin is lawlessness (1 John 3:4)
2) Sin is falling short of the glory of God (Romans 3:23)
3) Sin is revolting against God (Isaiah 1:2)
4) Sin is unbelief; it makes God a liar (1 John 5:10)
5) Sin is going your own way, planning your life according to your own will, without seeking the will of God (Isaiah 53:6)
6) All unrighteousness is sin (1 John 5:17).
Sin is a folly to deceive you, a force to destroy you, and a fact to condemn you. Sin is a volitional act of disobedience against the revealed will of God."
(This is From : Bible Foundation Course Lesson 05- 02)