In the Old Testament we find many laws which God gave to His people Israel. In the "Ten Commandments" which are found in Exodus, chapter 20, God commanded us to honour our parents, and to not murder, commit adultery, steal or lie, He also gave many other moral laws, one of which was, "You shall love your neighbour as yourself." (Leviticus 19:18). Jesus did not change any of these God-given laws, but he perfected them by explaining there real purpose.
For example, Jesus said that if anyone looks lustfully at a woman, not his wife, he is guilty of adultery. Thus, while the old commandments condemned the evil act, Jesus condemned the evil in the heart. He commanded truthfulness in speech, and forbade swearing, saying that one's every word should be as true as an oath. He told His followers that not only must they love one another but also their enemies, and must pray for those who kill them. He bans drunkenness and every form of immorality and he said that God's children must be perfect as their Father in heaven is perfect. No standard could be higher than that.
Jesus also gave a rule of conduct which is applicable in all lands and in all ages, namely: "Whatever you wish that men would do to you, do so to them; for this is the law and the prophets." (Matthew 7:12). Because of its great value this has often been called the "Golden Rule". This perfect and complete principle does not forbid doing wrong to others, rather it encourages doing all the good to others that we would like them to do to us.
All of the teachings of Jesus can be summed up in the one word "love." The love of Jesus Christ was perfect love, and he commanded his disciples to love one another as he loved them. Christians well know that they do not have this Christlike love in themselves, but when they remember how Christ loved them and died for them, they in turn will love others. The Spirit of Christ is the Spirit