What is sin? An apparently simple question brings a wide array of responses. Everything from smoking to cussing to committing murder would immediately come up. Things such as lying, stealing and committing fraud would certainly be mentioned. Certainly all these things represent behavior NOT in alignment with the Word of God, and thus be sins. But, the more important issue is that of understanding the simple, yet profound, concept of sin.
In its least common denominator, sin is the manifestation of either a lack of faith or a lack of love. Not believing what God says is of course sin, for it is impossible to please God without faith in Him and His Word. When we allow fear or arrogance to disrupt our ability to trust in God, we are guilty of sinning.
The two great commandments are basically made up of love for God, your neighbor and yourself. When we allow things to come up in our lives which are more important than God or are destructive to our neighbor or ourselves, we are guilty of sin.
Rather than trying to document everything that is a sin (the law) and trying to fulfill it perfectly, it is far better to concentrate on believing God's Word and loving Him with all our heart, soul, mind and strength and our neighbor as ourselves. Rather than imposing a set of regulations upon our thinking and actions (the law), it is far better that we seek to devote ourselves more and more each day to loving God and each other.
Some of the most legalistic people I have ever met were some of the biggest sinners. In their vain attempt to be perfect, they manifested no love but were in fact incredibly intolerant toward the weaknesses of others. The Pharisees were very righteous people but they were, in the words of Paul, chief sinners.
When attacking sin in our lives, we should not so much look at the individual things we do wrong but rather why we fail to manifest faith in the Word of God or fail to fully devote ourselves to Him and to manifesting His love to each other. God does not look on the outward part of us but rather upon our hearts. That is why we must strive to have within us undiluted and pure faith along with abounding love that ties up and keeps in check our selfish and vain desires.
Jesus Christ paid for our sins 2000 years ago at Calvary. His blood has washed us and made us righteous in God's sight. The most destructive thing we could do in light of this would be to again impose and enforce the Law He gave His life to make of none effect. Get saved, renew our minds to the Word of God , love God with every fiber of our being and love each other fervently. These are the things God desires of us and in turn put to rest the sin problem.