Answer
In John 3:6, Jesus says, “That which is born of the flesh is flesh, and that which is born of the Spirit is spirit” (ESV). This statement is part of Jesus’ response to Nicodemus, a ruler of the Jews, who had come to Jesus by night to converse with Him.
John records that Nicodemus started the conversation by saying, “Rabbi, we know that you are a teacher who has come from God. For no one could perform the signs you are doing if God were not with him” (John 3:2). Nicodemus probably came at night because he feared being rejected and ostracized by his own religious community. Nicodemus is also coming in spiritual darkness. Such is the case with everyone who has not been illumined by the radiant light of the Holy Spirit.
Nicodemus recognized that God is “with” Jesus, but he does not know that Jesus is God (John 1:1, 14). This is disappointing because Nicodemus mentioned the signs Jesus was performing (see John 2:23; 3:2). These signs should have revealed who Jesus is. Jesus wastes no time getting to the heart of Nicodemus’s need.
Jesus told Nicodemus, “Very truly I tell you, no one can see the kingdom of God unless they are born again” (John 3:3). The Greek phrase for born again can also be translated as “born from above” (as the NRSV renders the phrase). Both translations are sufficient. The idea is that sinners, including Nicodemus, need to be regenerated—or spiritually reborn—by the Holy Spirit (see Titus 3:5). Notice that the imperative to be born again is given to Nicodemus, a religious teacher of Israel (John 3:10). If he needs to be born again, how much greater is our need?
Nicodemus seemingly misunderstood Jesus’ words: “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?” he asks (John 3:4, ESV). It is doubtful that Nicodemus believed that Jesus wanted him to reenter his mother’s womb. It is much more likely that Nicodemus asked Jesus an asinine question to flesh out the true meaning of the phrase born again. Nevertheless, Nicodemus continued to misunderstand Jesus (verse 9).
In response, Jesus restates Himself: “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit” (John 3:5–6, NKJV). Here, the words born of water and the Spirit displace born again. Many interpreters use verse 6 to interpret verse 5, so that born of water refers to physical birth. This interpretation, however, does not fit the immediate context since there is a parallel between verses 3 and 5. So, if verse 3 refers to one birth, then verse 5 must also refer to one birth—a spiritual birth (cf. Ezekiel 36:25–27).
The word flesh in John 3:6 refers to the human body and human nature, as it does in John 1:14. The idea is that like produces like. In other words, human birth produces people who belong to an earthly family, but not to the family of God (John 1:12). It is the Holy Spirit who produces a new birth that makes us children of God (cf. John 6:63; Romans 8:16).
Because of his role as a teacher of Israel, Nicodemus should have understood the need for a new birth and God’s promise that He would give His people a new heart and a new nature. He should have understood spiritual matters, but as long as his thinking was mired in the physical level, he could not understand the spiritual truth Jesus expressed. That is why, in John 3:7, Jesus says, “Do not marvel that I said to you, ‘You must be born again’” (ESV).
