Whoever (so also New English Bible; New American Bible “Any man who”) is literally “if anyone,” an expression equivalent to whoever in English.

Whoever is willing to do what God wants is more literally rendered in Revised Standard Version “if any man’s will is to do his will.” Good News Translation transforms the noun “will” into a verb phrase is willing to do. The ambiguous expression “his will” is made explicit and translated as a verb phrase what God wants. New English Bible clears up the ambiguity by translating “the will of God,” substituting a noun phrase where Good News Translation has a verb phrase. Phillips (“If anyone wants to do God’s will”) is similar.

It is possible to render more or less literally the expression Whoever is willing to do what God wants and still miss the point of this passage, for in some languages “to be willing to do” may not suggest actually doing a thing, but merely having a favorable attitude toward doing it. In such cases it may be necessary to say “If anyone actually decides to do what God wants” or “If anyone is ready to obey God.”

Will know whether what I teach comes from God or whether I speak on my own authority is literally “will know concerning the teaching, whether it is from God or I am speaking from myself.” In this sentence “concerning the teaching” is obviously a reference to Jesus’ own teaching, and Good News Translation translates this phrase what I teach. The phrase “from myself” is taken by Good News Translation (so also Moffatt) to mean on my own authority. This meaning is obviously intended in other modern translations, though they translate the phrase in different ways.

The grammatical structure of verse 17 is rather complex, for it involves a number of embedded clauses. It may be useful to break the contents of this verse into two or more sentences, for example, “If anyone is ready to do what God wants him to do, then he will know about what I teach. He will know whether God is the one who instructed me in what I say or whether I speak just on my own” or “… whether these things come just from my own head.”

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 .