John's Testimony about Jesus from Jesus as Seen by John

 How confusing! The gospel is attributed to the John the Apostle who never appears in the gospel. The John who appears as a character is John the Baptist. One thing for certain, John the Baptist is not out for his own glory; all he does is point the way to Jesus. After Jesus' conversation, we come upon this story told in John 3:22:36:

After this, Jesus and his disciples went out into the Judean countryside, where he spent some time with them, and baptized. Now John also was baptizing at Aenon near Salim, because there was plenty of water, and people were coming and being baptized. (This was before John was put in prison.) An argument developed between some of John’s disciples and a certain Jew over the matter of ceremonial washing. They came to John and said to him, “Rabbi, that man who was with you on the other side of the Jordan—the one you testified about—look, he is baptizing, and everyone is going to him.”  To this John replied, “A person can receive only what is given them from heaven. You yourselves can testify that I said, ‘I am not the Messiah but am sent ahead of him.’ The bride belongs to the bridegroom. The friend who attends the bridegroom waits and listens for him, and is full of joy when he hears the bridegroom’s voice. That joy is mine, and it is now complete. He must become greater; I must become less.”
 The one who comes from above is above all; the one who is from the earth belongs to the earth, and speaks as one from the earth. The one who comes from heaven is above all. He testifies to what he has seen and heard, but no one accepts his testimony. Whoever has accepted it has certified that God is truthful. For the one whom God has sent speaks the words of God, for God gives the Spirit without limit. The Father loves the Son and has placed everything in his hands. Whoever believes in the Son has eternal life, but whoever rejects the Son will not see life, for God’s wrath remains on them.(NIV)

The conversation with Nicodemus took place in Jerusalem which is about 3500 feet above sea level. We don't always think of the city as being in the mountains, but I can personally attest to the fact that it can really snow there. Just east of Jerusalem is the Jordan river; not far as the crow flies, but several miles down a winding road to well below sea level. This is where Jesus and his disciples went. The passage tells us that Jesus and his disciples were baptizing (although we see in the next chapter that the baptizing was done by the disciples, not Jesus). John and his disciples were doing their work in the same area. 

The passage states that a Jew got into an argument with some of John's disciples over ceremonial washing. The disciples came to John, but the question regarding washing never came up; they wondered why more people were going to Jesus than were coming to John.  John states that a man can only receive what he is given from Heaven; from God. He had already announced that he was not the Messiah but a forerunner. Then he begins to teach his disciples. He uses the analogy of the bridegroom and the best man. The best man is happy for the bridegroom; he is not jealous. He wants the bride and groom to be happy and successful. Then John says in effect, Jesus is the bridegroom and he must increase while I must decrease. He is a real hero of mine. He knows his place. He is not suffering from a low self image, he just really understands who he is -- and who Jesus is; a realist.

John continues his testimony about Jesus; the one from above is over all. John had earlier testified that Jesus was the one sent down from heaven. Now he states that Jesus is above all. Most of us are of the earth and therefore speak of the things of earth; an earthly language. We speak this way because this all we really understand. But Jesus, who came from above, speaks of what he knows -- a spiritual language -- and people reject it; they don't understand it. The apostle Paul discusses this in his first letter to the Corinthians when he says that without the presence of the Holy Spirit, we can't understand spiritual things. Then John states that those who do receive Jesus' testimony actually certify that God is telling the truth; Jesus is truth and he speaks the word of God. Finally John says that Jesus has received the Holy Spirit without limit. 

Finally John concludes with the statement that God had given everything to Jesus. Why? because the Father loves the Son. Those who believe in Jesus and what he says have eternal life. Those who reject Jesus and his message are under God's wrath. When John discusses acceptance of Jesus, the idea has to do with obedience to his message, an rejection refers to disobedience. He is not discussing mere intellectual assent.