"Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbor as thyself: I am the Lord" (Leviticus 19:18).
Many people have mistakenly rejected or neglected the Old Testament on the basis that it speaks about a vindictive God of judgment in contrast to the New Testament God of love manifest in Jesus Christ. This perspective, however, is completely wrong.
One day a lawyer asked Jesus: "Master, which is the great commandment in the law? Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbor as thyself. On these two commandments hang all the law and the prophets" (Matthew 22:36-40).
Both of these commandments were recorded, of course, in the Old Testament. The first one in Deuteronomy 6:4-5 is perhaps the most revered of all passages to the Jews: "Hear, O Israel: The Lord our God is one Lord: And thou shalt love the Lord thy God with all thine heart, and with all thy soul, and with all thy might." The second great commandment is the one in our text for the day. This law is buried deep in the Pentateuch, in the unlikely heart of the book of Leviticus. In the New Testament it is even called "the royal law" (James 2:8).
Thus, the great underlying theme of the Old Testament is love -- love for God and love for others -- and this truth is stressed by Christ Himself in the New Testament. Even greater is God's eternal love which was ours from before the world and which will never end. "The Lord hath appeared of old unto me, saying, Yea, I have loved thee with an everlasting love: therefore with lovingkindness have I drawn thee" (Jeremiah 31:3). HMM