John Calvin Commentary John 3:10

"Jesus answered and said unto him, Art thou the teacher of Israel, and understandest not these things?" — John 3:10 (ASV)

Thou art a teacher of Israel. As Christ sees that he is spending his time and effort to no purpose in teaching such a proud man, he begins to rebuke him sharply. And certainly, such people will never make any progress until the wicked confidence with which they are puffed up is removed.

This is, very appropriately, placed first; for in the very matter where he chiefly prides himself on his sharpness and wisdom, Christ censures his ignorance. He thought that not admitting something to be possible would be considered proof of seriousness and intelligence, because a person is considered foolishly gullible who agrees with what another tells him before he has fully investigated the reason.

But still Nicodemus, with all his authoritative arrogance, exposes himself to ridicule by more than childish hesitation about the fundamental principles. Such hesitation, certainly, is contemptible and shameful. For what religion do we have, what knowledge of God, what rule for living well, what hope of eternal life, if we do not believe that humanity is renewed by the Spirit of God?

There is an emphasis, therefore, in the word these; for since Scripture frequently repeats this part of doctrine, it should not be unknown even to the newest beginners. It is utterly unbearable that anyone who professes to be a teacher in the Church of God should be ignorant and unskilled in it.