1 Corinthians 15:47-49 relates directly with the understanding that Jesus gave to Nicodemus in John chapter 3 verses 6 thru 13. 1 Corinthians says, “The first man is of the earth, **earthy: the second man is the Lord from heaven. As is the earthy, such are they also that are earthy: and as is the heavenly, such are they also that are heavenly. And as we have borne the image of the earthy, we shall also bear the image of the heavenly.
The point is being made in scripture that there is a new life for the person while on earth through Christ Jesus. If the first were/is spiritual, then the new life would be an earthy one. The point being that the spiritual life in Christ comes second, not first.
Now continuing with John 3:6-13. “That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. Marvel not that I said unto thee, Ye must be born again. The wind bloweth where it listeth , and thou hearest the sound thereof, but canst not tell whence it cometh , and whither it goeth : so is every one that is born of the Spirit. Nicodemus answered and said unto him, How can these things be ? 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? And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven.”
Jesus says in verse 11 *Verily, verily, I say unto thee, We speak that we do know, and testify that we have seen; and ye receive not our witness. (John 3:11)
One can "testify" only what he has "seen", and what he knows.
Then He says in verse 12 **If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things? (John3:12)
Christ was qualified to testifyabout "heavenly things" because He has seen it, having come from there!
He said to a group of Jews elsewhere, Him being the Creator of Heaven and earth.
Ye are from beneath; I am from above: ye are of this world; I am not of this world. (John 8:23)
There is no one who can teach about Heaven like Christ because He was the only one that has come fromHeaven! The prophets, who have seen Heaven, saw it only in visions. And if they had authority to speak about Heaven because of what they had seen, how much more Christ could speak about Heaven and spiritual things having been the only Person that came down from there!
In that context He told Nicodemus to confirm the truth about being born again.
And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven. (John 3:11-13)
"The Son of man which is in Heaven" (John 3:13) simply means Christ belongs to Heaven, He has come from Heaven, and is going to Heaven. That is His place, and as Jesus saw Nathaniel under the tree praying (John 1:48) proves He can be in more that one place at a time.
Nicodemus did not argue with Christ (as he did about being born again,) when Christ told him "No man has ascended to Heaven", because he knew what Christ meant.
