It is significant that Jesus classified this as “a new commandment.” It was new in direction. It is a commandment particularly for Christians pertaining to their relationship as brothers and sisters in Christ. It does not pertain to one’s love for God or for his fellow man in general. It specifically focuses on love between followers of Christ.
This commandment was also new in scope. The Lord specifically instructed His followers to love one another “as I have loved you.” That evening He would be betrayed, and He would go to the cross the very next day for all of those who would follow Him as their Savior. He loves us enough to have died for us. That is the scope of His love, and that is the scope of the love that we, as His followers, are to have for one another. “By this we know love, because He laid down His life for us. And we also ought to lay down our lives for the brethren” (1 Jn. 3:16).
Thirdly, this commandment was new in purpose. It was pertaining to a specific group of people- Christians- that they should love each other to a specific degree- enough to die for one another- for the purpose of demonstrating Christ in themselves to the non-Christian world around them. We are to be obvious examples of Christianity in the way we live our lives before those who have yet to become Christians. Through our Christian lifestyle we can influence some toward belief in God and Christ and toward becoming Christians (Matt. 5:14-16; Phlp. 2:15). We are to do that purposefully. The love that we demonstrate toward our brothers and sisters in Christ is one way, a way commanded by our Lord, to do it.
We must never take our relationship with our brothers and sisters in Christ lightly. We must not be careless in the way we think of or treat one another. Our diligence in obeying this commandment is a mark of our personal faithfulness, and it could also make a difference in the salvation of somebody else’s soul…