Jesus tells Nicodemus that no one can see the kingdom of God unless they are born again. When Nicodemus misunderstands, Jesus explains that this rebirth is not physical but spiritual, born of water and the Spirit. He compares the Spirit’s work to the wind, which is invisible but evident in its effects.

Nicodemus struggles to understand, and Jesus rebukes him for failing to grasp spiritual truths despite being a teacher of Israel. Jesus reveals that He must be "lifted up" (a reference to His crucifixion) so that everyone who believes in Him will have eternal life, drawing a parallel to Moses lifting the bronze serpent in the wilderness.