John 17:13-21  Jesus prayed that He would be glorified so that the Father would be glorified.  He prayed that the Father would "keep" His disciples from evil and the evil one.. from sin and in holiness.  He has made the Father known to them.. He has given them the words that the Father gave to Him,  and He has loved them as the Father loved Him. 

Next, Jesus prays about what will make Him most joyful.. that they would have His "joy full in themselves."  

That joy will not be found in the "world".   The world will hate the disciples of Jesus because they do not belong to it anymore.  Twice Jesus says, "they are not of the world, even as I am not of the world." (v14 and v16)   Again, I find the words of EM Bounds helpful... 

"These disciples were not to be taken out of the world, but kept from its evil, its monster evil, which is itself. 'This present evil world'.  How the world seduces, dazzles, and deludes the children of men! His disciples are chosen out of the world, out of the world's bustle and earthliness, out of its all-devouring greed of gain, out of its money-desire, money-love, and money-toil. Earth draws and holds as if it was make out of gold and not out of dirt; as though it was covered with diamonds and not with graves." 

"They are not of the world, even as I am not of the world,"  Jesus emphasized...  Bounds writes, "Not only from sin and satan were they to be kept, but also from the soil, stain, and the taint of worldliness, as Christ was free from it."   He goes on to say.. "How pronounced, radical, and eternal was our Lord Christ's divorce from the world! How pronounced, radical, and eternal is that of our Lord's true followers from the world! The world hates the disciple as it hated his Lord, and will crucify the disciple just as it crucified his Lord.  How pertinent the question, Have we Christ's unworldliness? Does the world hate us as it hated our Lord? Are his words fulfilled in us?" (Emphasis mine)

Oh how we need the intercession of our Lord Jesus.. this great petition.. "Sanctify them in the truth; Thy word is truth."   This is His petition for us.. "I do not ask in behalf of these alone, but for those who believe in Me through their word; that they may all be one." 

Father, hear our prayer.. sanctify us in Your truth.. that we may be one... even as You, Father are in Christ and He is in You, may we also be in You "that the world may believe.. " and be saved. Amen