The things of this world (Jerusalem Bible “things in this world”; New English Bible “things on earth”) is literally “earthly things,” and the things of heaven (so also New English Bible) is literally “heavenly things.” The problem is to determine precisely what is intended by these expressions. The least complicated solution is to assume that the things of this world refers to the things that Jesus has already spoken to Nicodemus about, while the things of heaven points forward to what Jesus will now say to him. Jesus has drawn analogies between things that happen on earth and things that happen in the realm where God’s Spirit operates, but Nicodemus has failed to perceive the spiritual truths of which Jesus is speaking. Now, without the use of earthly analogies, Jesus will speak directly to Nicodemus about the things of heaven (perhaps verses 13-15). If the use of earthly analogies could not make Nicodemus understand and believe, how can he be expected to believe when Jesus speaks directly about the things of heaven?

It may be misleading to translate literally the things of this world. which would be understood in many languages to refer merely to particular physical objects. A more satisfactory equivalent may be “You do not believe me when I tell you about happenings here in this world” or “… what takes place here in this world” or “… what happens here on earth.” What follows must then be so translated as to provide the maximum of contrast; for example, “about happenings in heaven” or “about what takes place in heaven.”

You throughout this verse is plural, that is, “you all” and not simply Nicodemus alone.

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 .