Jesus shed light on the ten commandments, and gave a more in depth insight to what the commandments meant.  He says i Mathew 22:37 you shall love the Lord your god with all your heart and with all yur soul this is the Great Foremost Command, And a second like it, you shall love your neighbor as yourself.

On these two commandments depend the whole law of the prophets

The New commandment fulfills the whole law of the prophets and also shows your obeidience which glorifies the Father which is our purpose.  Because Jesus says in John 13:34 "A new commandment I give to you, that you love one another, even as I have loved you, that you also love one another. By this all men will know that you are My disciples, if you have love for one another." (a17"; ?> John 13:34)

 He says by this all men will know that you are my disciples, Which gives glory to the father.  

 We needed the new commandment that was added by Jesus.