Love the Lord your God with all your heart and with all your soul and with all your strength. This was the command to love God. Here is the commandment to love your neighbor as yourself. These commandments had been on the books from the beginning. Love, you see, is not merely a New Testament innovation.
Love is found from the beginning of the Bible to the end.
Many people wrongly think that the God revealed in the Old Testament is wrathful, whereas Jesus is loving. But in both Old Testament and New, we see God as a God of love. Be careful not to mistake the holiness of God for hatred. God is a God of holiness and a God of love. As I have loved you, so you must love one another.