Galatians 5:14“The entire law is summed up in a single command: "Love your neighbor as yourself."
Paul connects the concepts of the previous verse to the law itself. He does this to add credibility to his argument for those who cling to the Jewish traditions. This shows that the Sadducees and Pharisees of that time had really gotten it all wrong. The real purpose of God’s law – the heart of the matter – had nothing to do with outward expression or behavior, or the proper fulfillment and performance of ritual. The heart of the matter is LOVE and a RELATIONSHIP built on love. Even the concept of being able to sum up the entire law, the hundreds of commandments that make up the Torah, in a single sentence means the law was always intended to be used in the context of relationships – as something to help us understand our relationship with God, and each other, rather than something to box us in. The law was meant to serve man, not man to serve the law. If I see my friend and fellow Christian disobey the law (in this context, meaning he is walking in sin, falling short of what God has called him to do), my attitude should be “how can I help,” not condemnation.
This verse quotes the law itself – Leviticus 19:18 – which also serves to bring Jesus himself into the argument, for He used this verse to answer the question, “What is the greatest commandment?” (See Matthew 7:12 and Mark 12:31). If Jesus Himself had this attitude and concept in mind, how can we adopt a different conclusion?