15 I do not demand that thou shouldest take them out of the world, but that thou shouldest keep them out of evil. 16 They are not of the world, as I am not of the world.
17 Sanctify them by the truth: thy word is truth. 18 As thou hast sent me into the world, I also have sent them into the world;
Matthew Henry's Commentary on John 17:15-18
Commentary on John 17:11-16
(Read John 17:11-16)
Christ does not pray that they might be rich and great in the world, but that they might be kept from sin, strengthened for their duty, and brought safe to heaven. The prosperity of the soul is the best prosperity. He pleaded with his holy Father, that he would keep them by his power and for his glory, that they might be united in affection and labours, even according to the union of the Father and the Son. He did not pray that his disciples should be removed out of the world, that they might escape the rage of men, for they had a great work to do for the glory of God, and the benefit of mankind. But he prayed that the Father would keep them from the evil, from being corrupted by the world, the remains of sin in their hearts, and from the power and craft of Satan. So that they might pass through the world as through an enemy's country, as he had done. They are not left here to pursue the same objects as the men around them, but to glorify God, and to serve their generation. The Spirit of God in true Christians is opposed to the spirit of the world.
Commentary on John 17:17-19
(Read John 17:17-19)
Christ next prayed for the disciples, that they might not only be kept from evil, but made good. It is the prayer of Jesus for all that are his, that they may be made holy. Even disciples must pray for sanctifying grace. The means of giving this grace is, "through thy truth, thy word is truth." Sanctify them, set them apart for thyself and thy service. Own them in the office; let thy hand go with them. Jesus entirely devoted himself to his undertaking, and all the parts of it, especially the offering up himself without spot unto God, by the eternal Spirit. The real holiness of all true Christians is the fruit of Christ's death, by which the gift of the Holy Ghost was purchased; he gave himself for his church, to sanctify it. If our views have not this effect on us, they are not Divine truth, or we do not receive them by a living and a working faith, but as mere notions.