Charles Spurgeon Commentary John 3:10-12

"Jesus answered and said unto him, Art thou the teacher of Israel, and understandest not these things? Verily, verily, I say unto thee, We speak that which we know, and bear witness of that which we have seen; and ye receive not our witness. If I told you earthly things and ye believe not, how shall ye believe if I tell you heavenly things?" — John 3:10-12 (ASV)

Jesus answered and said unto him, Art thou a master of Israel, and knowest not these things? Verily, verily, I say unto thee, We speak that we do know, and testify that we have seen; and ye receive not our witness. If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things?

The Saviour essentially told Nicodemus that He did not come to argue or reason with him, but to bear witness to absolute certainties, of which He Himself was absolutely sure.

So He said to him, "If you do not receive our witness concerning these things, which lie on the very threshold of the kingdom"—yet, note, He had been speaking about regeneration, the great mystery of the new birth—"it is no use going on to still higher themes."

Therefore, it is evident that the kingdom of Christ requires great faith—faith on its very threshold—to believe the wondrous mystery of the new birth, and still greater faith as deeper truths, the more heavenly things of the kingdom, are revealed to us.