You worship that which you don't know. We worship that which we know; for salvation is from the Jews.
But why does he say that it was from the Jews, when it was rather deposited with them, that they alone might enjoy it? He alludes, in my opinion, to what had been predicted by the Prophets, that the Law would go forth from Zion, (Isaiah 2:3; Micah 4:2,) for they were separated for a time from the rest of the nations on the express condition, that the pure knowledge of God should flow out from them to the whole world. It amounts to this, that God is not properly worshipped but by the certainty of faith, which cannot be produced in any other way than by the word of God. Hence it follows that all who forsake the word fall into idolatry; for Christ plainly testifies that an idol, or an imagination of their own brain, is substituted for God, when men are ignorant of the true God; and he charges with ignorance all to whom God has not revealed himself, for as soon as we are deprived of the light of his word, darkness and blindness reign. 