Jesus spoke to the Pharisees again may be more literally rendered “therefore Jesus spoke to them again saying.” “Therefore” represents a transitional particle (oun), and the participle “saying” after the finite verb “to speak,” indicates that direct discourse is to follow. Good News Translation specifically identifies the persons referred to by the pronoun “they” (the Pharisees), since a new section begins here.
The locale and the persons to whom Jesus is speaking are both vague, though in verse 20 we learn that Jesus said all this as he taught in the Temple, in the room where the offering boxes were placed. The last time Jesus was indicated as speaking was in 7.38 (considering, of course, that 8.1-11 is completely parenthetical). There he was apparently addressing the crowds who had come to the Temple for the feast. However, the crowd which was mentioned some eight times in Chapter 7 is not mentioned at all in Chapter 8. So it is possible that the present discourse is addressed to the Pharisees, the last group mentioned (7.47). They are mentioned again in the following verse, but the translations which make the pronominal reference of “them” explicit generally supply “the people” (so Phillips, New English Bible, Jerusalem Bible).
The I am statement of Jesus is here followed by a predicate, the light of the world. (On the use of I am in the Gospel of John, see comments at 4.26.) I am the light of the world is often rendered “I am the one who gives light to people in the world” or “I am the one who causes light for people of the world.” It is important to avoid a translation which would equate Jesus with the sun. Unfortunately, such a thing has happened in some literal translations of this passage.
Whoever follows me must be understood in the sense of “whoever becomes my disciple.” It is often expressed more clearly in some languages as “if anyone becomes my adherent” or “… joins himself with me.”
The light of life means “the light that gives life” (Die Bibel im heutigen Deutsch “the light that leads to life”). In some languages the light of life may be rendered “the light that causes people to really live” or “the light that shows people how they may live.”
In Greek the negative statement will never walk in darkness precedes the positive statement will have the light of life; but for English style it is more natural to state the positive first and then the negative. (On the meaning of light and darkness see 1.4-5.) Will never walk in darkness may be rendered in some languages “will never walk where it is dark” or even “will never walk in places where they cannot see.” Some translators want to express will never walk in darkness as “will never live in ignorance” or “… in ignorance of what God wants them to do.” However, this is not really the meaning of the contrast between light and darkness in this special biblical sense. It is not advisable to change completely these figurative meanings, based upon such pervasive usage as the contrast between light and darkness suggested in the biblical message.
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 .