<p>3:12 <i>If I told you earthly things and you do not believe, how shall you believe if I tell you heavenly things?- </i>What were these earthly things that Nicodemus did not believe? In the same as Paul at times 'says things in human terms', so the Lord had likened the new birth to the earthly analogy of insemination, pregnancy and birth. Nicodemus failed to believe that; and so there was no point in telling him heavenly things. He needed to be born from above, from Heaven (:5); but there was no point telling him about the things of Heaven if he refused to believe and grasp the simple requirement for new birth, expressed as it had been in earthly language. The Lord is saying in more abstract terms what Paul had in view when he writes to his converts of how he cannot write to them of the meat because they can't even grasp the milk.</p><p>But I suggested on :11 that these words of the Lord may also be applicable to John personally in his preaching of the Gospel. He chooses to record the more heavenly, spiritual sayings of the Lord, whereas the synoptics record His more direct, earthly statements. These words would therefore be true of John too, as the Lord's representative. He had told his audience earthly things, explained the Gospel history just as e.g. Mark had done, in straightforward language. And they had not believed. So there was little chance they were going to now believe His presentation of the more Heavenly words of the Lord.</p>