To love others was not a new commandment, but to love others as much as Christ loved others was revolutionary. Now we are to love others based on Jesus' sacrificial love for us. Such love will not only bring unbelievers to Christ; it will also keep believers strong and united in a world hostile to God. Jesus was a living example of God's love, as we are to be living examples of Jesus' love.
John 13:34So now I am giving you a new commandment: Love each other. Just as I have loved you, you should love each other.