John 13:34 – 35
English Standard Version (ESV)
34 A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. 35 By this all people will know that you are my disciples, if you have love for one another.”
From BibleGateway.com: http://www.biblegateway.com/passage/?search=John 13:34-35&version=ESV