This verse is in the form of a general statement, similar to a parable. A self-evident truth from everyday life is used to explain what Jesus has just said.

In Greek verse 6 is literally “that which is born of the flesh is flesh, and that which is born of the spirit is spirit.” John is not contrasting two aspects of human nature. Rather, he is speaking of two orders of existence, that of the physical world and that of the world of the Spirit. So “the flesh” is best taken as a reference to human parents, and “the spirit” as a reference to God’s Spirit, who brings about spiritual birth. Goodspeed makes this explicit: “Whatever owes its birth to the physical is physical, and whatever owes its birth to the Spirit is spiritual.” The entire verse is a kind of parable in which Jesus makes an analogy between a familiar experience in this world and that which happens in the realm where God’s Spirit works: human parents give life to their children, but only the Spirit can give spiritual life.

It is difficult in some languages to speak of something being “born physically” or “born spiritually,” because such abstracts as “physically” or “spiritually” do not exist as adjectives or adverbs. However, much the same type of meaning may be communicated in a different form, for example, “Our human parents give birth to our bodies” or “A man gets his body from his human parents” or “A man receives his body from his father and mother.” In a parallel manner one may say “the Spirit of God gives birth to the spirit in us” or “… causes us to have spirit.” Or it may be possible to say “Our parents cause our body to have life, but the Spirit of God causes our spirit to have life.” Care must be taken in the use of singular or plural in referring to “spirit” or “spirits” in order not to suggest that each person has a number of different spirits. Rather, there should be simply one spirit for each individual. This passage refers, of course, to man’s spiritual nature or capacity.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .