New Defender's Study Bible Notes
3:5 of water and of the spirit. “Water and the Spirit” here has the connotation of “water, even the Spirit.” The death and rebirth illustrated by John’s baptism, in which Nicodemus and his colleagues on the council had been so interested (John 1:25) was merely symbolic of rebirth in the Spirit. Some expositors have equated the “water” here with the Word and others have taken it to mean the water in the mother’s womb, but the context surely refers to baptism, and that is certainly what Nicodemus would have understood it to mean. The essential conclusion of Christ’s reply was that regeneration by the Holy Spirit was prerequisite to entering the kingdom of God. Paul used the same baptismal figure of the new life in Romans 6:4 and called it “the washing of regeneration” in Titus 3:5.
3:6 spirit. The flesh and the spirit are in perpetual conflict (Genesis 6:3; John 1:13; I Corinthians 15:50; Galatians 5:16-25).