"No one has ascended to heaven but He who came down from heaven, that is, the Son of Man who is in heaven. And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in Him should not perish but have eternal life. For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved. He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil. For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed. But he who does the truth comes to the light, that his deeds may be clearly seen, that they have been done in God."
The idea in verse 13 is that no one had ascended to heaven to learn of these "heavenly things" that Jesus was about to speak. How is Jesus knowledgeable of "heavenly things"? Because He is the One who came down from heaven to reveal!
The phrase at the end of the verse ("the Son of Man who is in heaven") is difficult since Jesus was clearly on Earth speaking with Nicodemus at that moment. The most logical explanation to this apparent difficulty seems to be that the words "who is in heaven" were added by the apostle John as he wrote toward the end of the first century, for at that time, Jesus was in heaven.
In the next several verses, Jesus commented on the bronze serpent from Israel's past and noted some similarities between Him and it. Then Jesus made His well-known but often misunderstood statement regarding faith - "whoever believes in Him should not perish but have everlasting life." Since we have studied John 3:14-16 in depth in two past lessons, we will not repeat ourselves here. Please refer to the archived lessons "The Bronze Serpent & Jesus Christ" and "'The Greatest' Passage" from February 18th and 19th, 2005, for an analysis of these verses.
John 3:17 makes it clear that Jesus did not come to Earth to condemn mankind. He came because man was already condemned and in need of a Savior. Tragically, despite the fact that He is a perfect Savior, the majority of the human race refuses to look upon the Son of God and faithfully obey Him in order to be saved! Christ's mission at that time was "to seek and save the lost" (Luke 19:10). When he returns, He will then come as a Judge (cf. Matt. 25:31ff).
The Lord then stated that he who believes in Christ (literally, "keeps on believing") is not under condemnation (John 3:18). One who truly believes is prompted by his faith to obey the Lord (cf. 3:36). All others are already condemned as disobedient unbelievers.
As this section closes, Jesus affirmed that He came to lead men from darkness to light, but not all accepted Him, being lovers of darkness since "their deeds were evil" (3:19). He went on to explain why those who practice evil hate the light--because it exposes their wickedness and their condemnation becomes obvious. Those who love the truth, on the other hand, seek out the light and in it find great satisfaction for it reveals that their lives are ordered by what is righteous and pleasing to God. They have no fear of the light because they know that the light will reflect the true character of their conduct; they are not afraid for anyone to see this.
Finally, Jesus spoke these words - "He who does the truth comes to the light..." (3:21). Truth should not be just something one knows; it should be something one does. Knowledge of the truth is useless without obedience.
Friends, are you lovers of light and truth? Are you obedient to the Son of Man and a true believer in Him?