In the first three verses of this chapter, we see Nicodemus, a Pharisee, come to Jesus and acknowledge that He is from God. Nicodemus comes at night, no doubt to avoid the persecution that he would have encountered if the other Pharisees knew he had come to see Jesus. He has seen the signs and wonders, and has believed, and he wants to learn more, so comes to Jesus, seeking answers.
Jesus tells him that to see God's kingdom, a person must be born again, or as some translations say, "born from above". To get an idea what Jesus is talking about here, look back at the following passage from chapter 1.
12 But as many as received Him, to them He gave the right to become children of God, to those who believe in His name: 13 who were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God. (John 1:12-13, New King James Version)
We can see that it is by believing and receiving Him that we have the right to become His children, born not of blood (or natural descent), not of flesh, and not because another person wills it, but because of God's will and plan.
Continuing on with chapter 3, we see that Nicodemus, not understanding all of this, asks Jesus how it is possible for a grown man to born again, since obviously he cannot return to the womb, and Jesus tells Nicodemus that one must be born of water and the Spirit.
Now some people believe that Jesus was speaking of baptism when he said, "born of water", however, there are at least two reasons that this interpretation doesn't really make sense. First, if we look again at John 1:12-13, we see that it is through receiving Him that we become God's children, it says nothing about baptism. Also, if we look at the very next thing sentence Jesus said to Nicodemus, it is "That which is born of the flesh is flesh, and that which is born of the Spirit is spirit." This would indicate that when Jesus says, "born of water" he is talking about the physical birth, and the water he refers to is the water of the womb.
He tells us that we must not only be born of water (natural birth), but that we must also be born of the spirit, which is done by believing in Him and receiving Him, which means to welcome Him into your life as who He really is, God. We may not fully understand this, and Jesus talks about this when He says that, "The wind blows where it wishes, and you hear the sound of it, but cannot tell where it comes from and where it goes. So is everyone who is born of the Spirit.” I believe that when He says that He is telling Nicodemus that just as one does not understand where the wind came from, we can't fully understand God's work in the New Birth, but we do know that His work is true. Ecclesiastes 11:5 expresses a similar statement about the work of God.
As you do not know what is the way of the wind,
Or how the bones grow in the womb of her who is with child,
So you do not know the works of God who makes everything.
(Ecclesiastes 11:5, New King James Version)
Nicodemus then questions more, wanting to understand how this can be, how it can happen. It would seem that he wants to believe, but that he still has doubts, and isn't quite sure yet.
Jesus' response to him is first a gentle rebuke for unbelief, but then He goes on to tell Nicodemus exactly what needs to happen in order for Nicodemus to receive this New Birth. Jesus did not hold out, demanding perfect, unwavering faith free of all doubts. Jesus saw that seed of faith and that desire to know more, and Jesus told Nicodemus what was needed.
Jesus talks of Moses lifting up the serpent in the wilderness, and says that He too must be lifted up in the same way, so that whoever believes in Him would not perish but have eternal life. To understand this illustration Jesus uses, we must look back into the Old Testament book of Numbers.
4 Then they journeyed from Mount Hor by the Way of the Red Sea, to go around the land of Edom; and the soul of the people became very discouraged on the way. 5 And the people spoke against God and against Moses: “Why have you brought us up out of Egypt to die in the wilderness? For there is no food and no water, and our soul loathes this worthless bread.” 6 So the LORD sent fiery serpents among the people, and they bit the people; and many of the people of Israel died.
7 Therefore the people came to Moses, and said, “We have sinned, for we have spoken against the LORD and against you; pray to the LORD that He take away the serpents from us.” So Moses prayed for the people.
8 Then the LORD said to Moses, “Make a fiery serpent, and set it on a pole; and it shall be that everyone who is bitten, when he looks at it, shall live.” 9 So Moses made a bronze serpent, and put it on a pole; and so it was, if a serpent had bitten anyone, when he looked at the bronze serpent, he lived. (Numbers 21:4-9, New King James Version)
Now, a serpent in scripture usually represents sin or evil, so why is Jesus using it here to point to Himself and His work on the cross? Well, the Bronze serpent in Numbers was a clear picture of the judgment for the the people's sin, and if we look at Colossians 2:13-14, we see that God nailed the judgment of our sin to the cross just as the symbol of the Isrealites judgment was put on that pole.
13 And you, being dead in your trespasses and the uncircumcision of your flesh, He has made alive together with Him, having forgiven you all trespasses, 14 having wiped out the handwriting of requirements that was against us, which was contrary to us. And He has taken it out of the way, having nailed it to the cross. (Colossians 2:13-14, New King James Version)
You see, it clearly tells us that the handwriting of requirements, which is the judgment scripture declares on our sin, was wiped out, taken out of the way, nailed to the cross. In the same way, the bronze serpent, the symbol of the judgment of their sin, had been put on the pole and lifted up.
The Bible also says in 2 Corinthians 5:21, "For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him." Jesus was made sin for us, and was nailed to the cross that we might become righteous in God's sight! So, in looking at the serpent which Moses lifted up, we see a clear picture, not only of the judgment of our sin, but, since a serpent represents sin, it is a picture even of the sin itself being nailed to the cross.
Another thing to notice is this, and it relates back to Nicodemus' apparent doubt mixed with the seed of faith. When the Israelites were judged with these serpents, and a person was bitten, they were not told that they had to do anything other than look to the serpent on the pole to be saved. They did not need to crawl over to it in their own strength, they did not need to beg, they did not need to bargain. It was not even required that they have unwavering faith that looking at the bronze serpent would save them. They simply had to have enough faith to do what they were told to do. They were healed even if what they were thinking was, "Well, I am not sure that this is really going to work, but Moses says that if I look at that thing I'll be saved from death, so I guess I should at least give it a try." Even if they had doubts, if they had enough faith to just do what they were told and hope for the best, they were saved.
It is the same with Jesus. He took our sin and the judgment for it and nailed it all on the cross with Him, and to be saved we simply have to do what He says, which is to look to Him for salvation, to receive Him. We may have doubts in our minds at times, but if we have even enough faith to just come to Him and ask, He will save us. If we will look to Him in spite of our doubts, that is enough faith to save us.
We may think that because we have a little doubt, that means we don't have faith, but in God's eyes, if we have enough faith to just look to Jesus even though we aren't sure, we have saving faith. It is in the act of looking to Him and receiving Him, even though we doubt and don't understand, it is in that act that we are saved, and it is in that act that our faith will be strengthened. If you are reading this and you want to come to Jesus, but like Nicodemus you are hesitating because of some doubt, I would urge you to put you faith in Jesus despite your doubt, look to Him and ask Him to save you. He will not disappoint you.
Perhaps the best known verse in this chapter is "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." (John 3:16). I believe though, that much value can be found in the context of this verse. Verses 15-18 taken altogether make it clear that all who believe in Him and look to Him to save them will be saved, but those who do not believe and therefore refuse to look to Him for salvation are condemned. Why would anyone choose not to look to Him? Verses 19-21 make it very clear, it is because they do not want their sin exposed. They do not want to come into the light, so they stubbornly refuse to look to Jesus and they die in their sin.
The rest of the chapter goes on to confirm all that Jesus said, as John the baptist points his own followers to Jesus, essentially telling them to look to Him. Then John also reiterates the main point of the passage as He says, " He who believes in the Son has everlasting life; and he who does not believe the Son shall not see life, but the wrath of God abides on him.” (John 3:36)
Lord, I thank you for taking the judgment for my sin upon yourself and nailing it to the cross, wiping out my debt. Lord, I pray for those who might read this, for those who already have looked to you for their salvation, I pray Lord that you will use this to increase their thankfulness to You for their salvation. For those who have yet to look to You Lord, I pray that they will realize their need. That they will see that sin has left them with a debt that they cannot pay, but which you have paid for them, and all they need to do is look to You and receive the salvation you offer. Lord I pray that you would help them to have enough faith to take action in spite of their doubts, to look to You even though they are unsure, and ask You to save them. In your precious name Jesus, Amen.