Sin is the transgression of the law. However, the Old Testament and New Testament concepts of sin are different, though the same definition applies to both. In the Old Testament, there was the Law of Moses; the Ten Commandments. According to the scriptures, this was to guide the children of Israel until the coming of the Messiah. So when Jesus came the law was cancelled: "Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace" (Ephesians 2:15). The law was annulled because it was weakened by the fleshly desires of man and it didn't make anything perfect (Hebrews 7:18-19). Galatians 3:24-26 says, "Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. But after that faith is come, we are no longer under a schoolmaster. For ye are all the children of God by faith in Christ Jesus." Hallelujah! Just as I stated earlier, the definition of sin remains the same in the New Testament. Jesus however gave us only one law and that is the law of love; "This is my commandment, That ye love one another, as I have loved you" (John 15:12). Every conscious act against love therefore is sin. "Does that mean the Law of Moses is irrelevant?" you may want to ask. Well, the Bible says, "For all the law is fulfilled in one word, even in this; Thou shalt love thy neighbour as thyself" (Galatians 5:14). The Lord Jesus reiterated the same truth in Matthew 22:36-40. The Law of Moses and those of the prophets are fulfilled in one word; LOVE! "…therefore love is the fulfilling of the law" (Romans 13:10). Sadly, many Christians around the world are ignorant of this truth and consequently live Old Testament lives in New Testament times. The Christian who is living by the Law of Moses today is as foolish as a lawyer who is still practising colonial laws. Moreover, the law was given to the children of Israel only, hence, any man who is not of Jewish descent has no business obeying the law (Romans 3:19). So, don't get caught in practicing mere religion; live rather in the revelation of the new creation.