John 17:12

While I was with them, I kept them in thy name which thou hast given me: and I guarded them, and not one of them perished, but the son of perdition; that the Scriptures might be fulfilled.

Thy name which thou hast given me ... Again, the compound title of John 17:3 is suggested.

I guarded them ... Jesus Christ successfully accomplished the work God gave him to do, choosing, instructing, guarding, correcting, and encouraging the Twelve; and he was then praying for them with all of his heart, adding prophetically that not one of them would be lost except Judas.

But the son of perdition ... This reference to Judas sheds light on the identity of "the man of sin" (2 Thessalonians 2:3), indicating that he will be another pretender ascribing to himself apostolic authority and power. Any self-styled "apostle" today must be judged in the light of these Scriptures.

That the Scriptures might be fulfilled ... refers to Psalms 41:9. See under John 13:2 and John 13:18.