John 17:12

12. While In the five ensuing verses Jesus contemplates his apostles in relation to their earthly dangers, as by him faithfully kept, (albeit that one is lost,) in the midst of a hated world, from which they must not be withdrawn, though while in it they are not of it. While… in the world Here, as throughout this intercession, his standpoint is beyond this world.

I kept them Kept them, not like a purse of coin, locked in an iron safe, as a mere thing; nor as a prisoner, locked in a bolted cell, as an unfree agent, but as a child is kept in a loved home, from which he is able to escape by a power of his own. Such keeping of a true free agent is intended to be sure only when the kept one prefers to be kept. No divine guardianship throughout the Bible engages to secure a Christian from voluntary apostacy.

The son of perdition Stier well remarks that wherever in the Holy Scriptures the figurative phrase child of an evil thing is used, it indicates the wilful, guilty, and fixed tendency of the being. So child of hell, Matthew 23:15; children of disobedience, Ephesians 2:2; so also man of sin, 2 Thessalonians 2:3. Son of perdition, therefore, indicates one who by his own wilful, guilty, personal tending, lands in final destruction. But it is plain, from the previous part of the verse, that this son of perdition was one of those whom thou gavest me, and was kept in thy name; and yet, in spite of that keeping, he was lost; and he became a final heir of perdition. Hence we have on this sacred record, presented in the very primal twelve, a type of genuine final apostacy in the Christian Church.

Scripture might be fulfilled This is the final good educed by God from the darkest evil: that therein his foreknowledge is verified, and God’s plans for his own conduct, which are conditioned upon the foreknowledge, are left underanged. The dark human side was for pure evil; the divine side is, that the unneeded and condemned sin does of itself fit in to the production of God’s best results.