“Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God. Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born? Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.” John 3:3–5
In John 3, Jesus uses the phrase “born of water” in answer to Nicodemus’s question about how to enter the kingdom of heaven. He told Nicodemus that he “must be born again” (John 3:3). Nicodemus questioned how such a thing could happen when he was a grown man. Jesus answered, “Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.” John 3:5
Being “born of the Spirit” is interpreted—as salvation which involves a new life that only the Holy Spirit can produce (2 Corinthians 3:6). But there are a couple of different schools of thought on what Jesus meant when He said, “born of water.” One perspective is that “born of water” refers to physical birth. Unborn babies float in a sack of amniotic fluid for nine months. When the time for birth arrives, that sack of water bursts, and the baby is born in a rush of water, entering the world as a new creature. This birth parallels being “born of the Spirit,” as a similar new birth occurs within our hearts (2 Corinthians 5:17). A person once-born has physical life; a person twice-born has eternal life (John 3:15–18, 36; 17:3; 1 Peter 1:23). Just as a baby contributes no effort to the birth process—the work is done by the mother—so it is with spiritual birth. We are merely the recipients of God’s grace as He gives us new birth through His Spirit (Ephesians 2:8–9). According to this view, Jesus was using a teaching technique He often employed by comparing a spiritual truth with a physical reality. Nicodemus did not understand spiritual birth, but he could understand physical birth so that was where Jesus took him.
The other perspective is that “born of water” refers to spiritual cleansing and that Nicodemus would have naturally understood it that way. According to this view, “born of water” and “born of the Spirit” are different ways of saying the same thing, once metaphorically and once literally. Jesus’ words “born of water and the Spirit” describe different aspects of the same spiritual birth, or of what it means to be “born again.” So, when Jesus told Nicodemus that he must “be born of water,” He was referring to his need for spiritual cleansing. Throughout the Old Testament, water is used figuratively of spiritual cleansing. For example, Ezekiel 36:25 says, “I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your impurities” (also Numbers 19:17–19; and Psalm 51:2, 7). Nicodemus, a teacher of the law, would have been familiar with the concept of physical water representing spiritual purification.
The New Testament, too, uses water as a figure of the new birth. Regeneration is called a “washing” brought about by the Holy Spirit through the Word of God at the moment of salvation (Titus 3:5; cf. Ephesians 5:26; John 13:10). Christians are “And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.” 1 Corinthians 6:11. The “washing” Paul speaks of here is a spiritual one.
Born of water is not a reference to water baptism. Baptism is nowhere mentioned in the context, nor did Jesus ever imply that we must do anything to inherit eternal life but trust in Him in faith (John 3:16). Water baptism is an outward sign that we have given our lives to Jesus, but not a requirement for salvation (Luke 23:40–43).