We don't think sin is all that bad. Everybody does it. Nobody is perfect. Often we can blame someone else for pushing us into it. (e.g., I wouldn't have road rage if the other people would drive better...)
Sin is rebellion against our Holy Creator. It is a treasonous betrayal of our All Wise God. It is spitting in the face of our Loving Savior. It is thumbing our nose at our Eternal Judge.
Besides that, sin is antithetical to our hope of eternal salvation.
(Romans 6:1-2) What shall we say then? Shall we continue in sin that grace may abound?Jesus died to save sinners from their sins. If someone is not sensitive about sin in his life - in what way is he saved? If a person has no victory over sin in his life, but continues in the same patterns of sin - it is evidence that his profession of faith was just words - his supposed faith is dead.
2 Certainly not! How shall we who died to sin live any longer in it?
(1John 2:29) If you know that He is righteous, you know that everyone who practices righteousness is born of Him.
(1John 3:6-8) No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him.
7 Dear children, do not let anyone lead you astray. He who does what is right is righteous, just as he is righteous.
8 He who does what is sinful is of the devil, because the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the devil’s work.
(James 2:20) But do you want to know, O foolish man, that faith without works is dead?We don't take sin seriously enough. Our goal is to glorify Christ! We will not get that done by repeating happy platitudes - suggesting we love Him and adore Him - while by our daily actions we dishonor Him and betray Him.
To love Jesus is to hate our sin - like He does.
God said, "You shall be holy, for I the LORD your God am holy." (Leviticus 19:2)