Love does no harm to a neighbor. Therefore love is the fulfillment of the law. Romans 13:10
The law in Jewish understanding wasn’t just the 10 commandments or the other regulations. The first five books of the Old Testament was called, “The Book of the Law,” and often the whole Old Testament was called, “The Law.” The law was part of the covenant between God and his people. They didn’t keep the law in order to become God’s people but rather because they were God’s people they were supposed to keep it.
The covenant or agreement God made with his people at Mount Sinai was that God would protect and provide for Israel and they were to keep the regulations in the law. History would prove that Israel was never able to keep their part of the covenant and ultimately God made a new covenantal agreement between himself and Jesus. When we become Christians we are placed “in Christ Jesus” so the covenant is kept.
Most of the regulations in the Old Testament aren’t renewed in the New Testament. We aren’t required to make sure our clothes aren’t woven with two kinds of material or that our fields aren’t harvested to the edges. Instead, we show that we are the people of God, by our love. This fulfils or completes the law.
However, we still have many Christians who think they can fulfil the law through their good deeds. The Israelites couldn’t do it and neither can we. As we trust God and live “in Christ” we are empowered to love and then we can keep the new commandment that Jesus gave, “Love one another. As I have loved you, so you must love one another. By this all men will know that you are my disciples” (John 13:34-35).