"I do not ask for these only, but also for those who will believe in me through their word,  that they may all be one, just as you,

Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me.The glory that you have given me I have given to them, that they may be one even as we are one, I in them and you in me, athat they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me.  Father, I desire that they also, whom you have given me, may be with me where I am, to see my glory that you have given me because you loved me before the foundation of the world. O righteous Father, even though the world does not know you, I know you, and these know that you have sent me. I made known to them your name, and I will continue to make it known, that the love with which you have loved me may be in them, and I in them." (John 17: 20-26)

Dr. Sproul starts off this section discussing prayer and the need for it and does this by relating an experience shortly after becoming a Christian and meeting some people that knew how to pray. He then goes into the passage and focuses on the unity we as believers should have among ourselves and all the time remembering that there will be a time that we will be with Him forever in unity.(from the website: http://www.ligonier.org/learn/sermons/prayer-church/)

the audio file is located: http://www.ligonier.org/account/dashboard/sermon/108/download/