When disease is diagnosed, it is important to ask the question: 'Is it serious?' It is even more important to ask that question about the spiritual disease of sin. Many people will almost cheerfully admit to being sinners, because they have no idea what this means. They treat it as being 'just human nature', or they shelter behind the fact that 'everybody does it'. But those statements dodge the real issue: is sin serious? Here are some of the things the Bible says about you as a sinner.
You are debased
This does not mean that you are as bad as you can possibly be, nor that you are constantly committing every sin. Nor does it mean that you cannot tell right from wrong, or do things that are pleasant and helpful. But it does mean that sin has invaded every part of your nature and personality — your mind, will, affections, conscience, disposition and imagination. The heart is deceitful above all things and beyond cure. (Jeremiah 17:9) The root of your trouble is not what you do but what you are! You sin because you are a sinner.
You are defiled
The Bible pulls no punches here: For from within, out of men's hearts, come evil thoughts, sexual immorality, theft, murder, adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. (Mark 7:21-22) Notice that the list includes thoughts, words and actions. This shows that in God's sight all sin is equally serious: Some people limit their idea of sin to things like murder, adultery and robbery, but the Bible makes it clear that we have no right to think of sin in this way. Sin is anything that fails to meet God's perfect standards. Anything we say, think or do that is less than perfect is sin. Now face up to this question: Who can say, 'I have kept my heart pure; I am clean and without sin'? (Proverbs 20:9) Can you? If not, you are defiled.
You are defiant
The Bible teaches that sin is lawlessness, (1 John 3:4) deliberate rebellion against God's authority and Law. No civil law forces you to lie, cheat, have impure thoughts, or sin in any other way. You choose to sin. You choose to break God's holy Law. You deliberately disobey Him and that is serious, because God is a righteous judge who expresses His wrath every day. (Psalm 7:11) God can never be 'soft' about sin, and you can be sure that not even one sin will go unpunished.
Some small part of God's punishment of sin comes in this life (though we may not recognise it). But the final punishment will be inflicted after death, when on the Day of Judgement each one of us will give an account of himself to God. (Romans 14:12)