The other day, as I was teaching a P.E. class, I had a student who was typically a handful. When he came in, he did marvelous for me. I made a point to brag on him to his teacher, making sure that he was within earshot so he could overhear the words of praise. I could immediately see the effect it had on him in his face and in the way he carried himself.
Sometimes allowing someone to "overhear" can have a very powerful effect on them. I believe that this is what is happening in the Lord's prayer of John 17. I like to call the prayer of John 17 the Lord's Prayer. Some call it his high priestly prayer. Whatever we call it, we need to remember that it is more than his prayer to God. It is preserved in scripture for us in order to us to "overhear" and receive a message from it.
In order to get the full effect of this, it may be helpful to change the third person pronouns (they, them, etc.) to second personal pronouns (you, your, etc.). Read this excerpt from John 17:13-18, 21-26 as though Jesus were speaking directly to you, and spend some time carefully reflecting on what our Lord is communicating to us.
"But now I go to the Father; and these things I have spoken in the world so that you may have My joy made full in yourselves. I have given you God's word; and the world has hated you, because you are not of the world, even as I am not of the world. I do not ask the Father to take you out of the world, but to keep you from the evil one. You are not of the world, even as I am not of the world. I have asked the Father to sanctify you in the truth; His word is truth. As the Father sent Me into the world, I also have sent you into the world. …I have asked the Father that you may all be one; even as the Father, is in Me and I in Him, that you also may be in Us, so that the world may believe that the Father has sent Me. The glory which the Father has given Me I have given to you, that you may be one, just as the Father and I are one; I in you and He in Me, that you may be perfected in unity, so that the world may know that He has sent Me, and loved you, even as the Father has loved Me. I desire that you be with Me where I am, so that you may see My glory which the Father has given Me, for the Father loved Me before the foundation of the world. Although the world has not known my Father, yet I have known Him; and you have known that He sent Me; and I have made His name known to you, and will make it known, so that the love with which the Father loved Me may be in you, and I in you."