"A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another." (John 13:34 KJV)
So what is new about this command? Well, compare it for a moment to the old one. "Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the LORD." (Leviticus 19:18 KJV) They look pretty similar. At least in the sense of loving one another or your neighbor. Neighbor has previously been expanded to include anyone you can consider to be your neighbor instead of a people that live or believe within a certain radius of where you are by Jesus and the story of the good Samaritan back in Luke 10:25-37. Look closely in specific as to how you are to love your neighbor. Notice "as thyself" verses "as I have loved you". Big difference? You bet! There may be a certain innate understanding that each of us has concerning how we ought to love someone else if we are measuring that love based on how we would like some of that. Yet to love as Jesus loves us? That is a whole new level. His love is unconditional. His love is full of an unmerited favor, or a grace. He love has mercy where we would expect to be much harsher with ourselves. Our love is all too often based on an understanding of the situation. His love knows all things. His love reaches into a past that we can never get back to. His love extends to a future that we cannot even see yet. To love as He loved us! That is a pretty tall order.
If the old testament was written to make it clear that we could never live up to the bar that God has set for us, then does this command increase or lower that bar? Duh, increase! Why? The point was not to be able to live up to it. The point was to trust all the more in God's sufficiency. He stretches us in this command so that He might come even closer to us to teach us even more. This gives us something to practice rather than something to ponder. We need not wonder if the love I am providing is sufficient. We now always know that it has room to grow. This gives the world something to recognize us by. Not our great discipline and mastery, but our ever reliance on the love that we first received from Jesus.