“For their sakes I sanctify Myself, that they themselves also may be sanctified in truth.” (John 17:19 )
“For their sakes.” We must recognize, guilty sinners as we are, that it is for us that He has done all this. “I sanctify myself,” says the eternal Son of God, the holy and pure One, the blameless and spotless One, the One whose supreme joy was to do the will of His Father. Can you imagine a greater contrast than that between “they” and “I”? And yet He says, “I sanctify myself,” which not only means the totality of His personality, but also that He did it voluntarily and willingly. There was nothing in us to recommend this; there was no motive that could arise from anything in us. Man in sin is so damned and hopeless that he does not want to be saved or even asks to be. No request ever went out from man to God for salvation; it has come entirely from God. “Here am I,” says our Lord. “Send Me.”
– Martyn Lloyd-Jones and Robert Backhouse, Walking with God Day by Day: 365 Daily Devotional Selections, (Wheaton, IL: Crossway, 2013).