23: An Examination of Light

Studies in the Gospel of John

Lesson 23: The Explanation of Light

John 8:12 -20


It is an interesting point of human nature that we take many very important things for granted: our jobs, an ample supply of clean drinking water, the autonomic nervous system in our bodies, the rotation speed of the earth, and so forth. But let me just cut to the chase and say that another of those very important things that we take for granted is light. Light is essential to life itself – not just for plants, but for human life as well. Psychologists have recently discovered that the absence of light has a direct bearing on depression. And light certainly determines how well we function as we move around, as we try to read and write, and so forth.


The reason that I bring all of that up is that “light” is the theme of John chapter 8. And in the verses to which we come in this study we find Jesus describing Himself in just that way. Look at verse 12:


Then Jesus spoke to them again, saying, I am the light of the world. He who follows me shall not walk in darkness but shall have the light of life.


Now to get this verse in its context, let’s review the contents of the chapter. In verses 1 through 11 we find “the exposure to the light. Then in verses 12 through 20 we find “the explanation of light. And in verses 21 through 29 we have “an examination of light.” In verses 30 through 47 we see “the extension of light.” And in verses 48 through 59 we see “the exit of light” (but not the “extinguishing of light)


In our last study we looked at “the exposure to the light” in verses 1 through 11 which the Pharisees and an adulterous woman both experienced. So as we come to verse 12 we find “an explanation of that light that Jesus shined on them. The beginning of that explanation is the promise that Jesus makes in verse 12.


Then Jesus spoke to them again, saying, “I am the light of the world. He who follows me shall not walk in darkness, but shall have the light of life.”


Here is another of the several places in the New Testament where Jesus uses the Old Testament name of God, “I Am” This is the name that God used when Moses demanded a name to give the Israelites when he was going to lead them out of Egyptian slavery in Exodus 3:14. And it speaks of “the all inclusive one.” When you come right down to it, we don’t have a lot of information in the Bible about God Himself. – even though we have everything we need to know – His omniscience, omnipresence, eternality, and so forth. But one of the purposes of Christ coming to earth was to show God to us. And as we have seen, one of the ways He did that was by comparing Himself to various things with which His original hearers were familiar – bread in chapter 6, water chapter 7, and now, in 8:12, “light.” And when He made these comparisons He always said, “I am”


In the first 11 verses Jesus had shined His light on the sin of the scribes and the Pharisees and the adulterous woman. And when the light came on it was obvious that they were as guilty as she was. J. Vernon McGee says, “when you turn on the lights all the rats and roaches and the bedbugs crawl away. Christ’s light exposed their sin, that’s why they had to leave. This is the highest claim that Jesus has made here in the gospel of John – because John used that very term to describe the Son of God in chapter one. Physical light is one of the most complicated things in the realm of human understanding. Scientists aren’t sure whether light is the absence of darkness or darkness is the absence of light. In some ways it acts like waves and in some ways it acts like particles of matter. Scientists and inventors, acting on both of these definitions have been able make remarkable inventions and discoveries. With the development of the ability to focus light waves very intently as a “laser beam” we have a means of producing high quality sound and microscopic surgery. So light, with all of its diversity, is an apt description of God.


Interestingly enough, most of the world today is content to walk only in the “reflected” light of God’s glory. Everything that is good socially, and politically is simply a reflection of the light of Jesus Christ in human affairs. The only reason we have hospitals, orphanages and other charitable organizations, is because of the biblical principles of righteousness instilled in society by Christians.

Even Charles Darwin is said on his deathbed, “even the atheist as his shipwrecked craft drifts toward native island hopes the missionary has beat him there.” And the reason we have problems in those areas is that we have wandered too far from the light. But in contrast to that, Christ’s promise is that those who follow Him will not be walking in darkness.


Now we have been talking about “the promise” that Jesus made, but in verse 13 we find the protest that the Pharisees made:


The Pharisees therefore said to Him, you bear witness of yourself. Your witness is not true.


This protest is based on an Old Testament principle stated in Deuteronomy 17:6 which said that any promise or accusation has to have two witnesses in order be valid. Of course they were misapplying that principle. It didn’t mean that one witness would never tell the truth, it only meant that there had to be two witnesses for it to be accepted as valid testimony.


Jesus touches on that misapplication as He gives the principle behind His statement in verses 14 through 18. In these verses He is going to use three reasons why His testimony is true. First, because of His purpose –


Jesus answered and said to them, “Even if I bear witness of myself, my witness is true, for I know where I came from and where I am going, but you do not know where I am from or where I am going.”


Jesus knew that His life did not begin when He came to Bethlehem as a baby – He had always existed with the Father. And not only that, He knew where He was going – back to the Father. Incidentally, in knowing that He sets Himself apart from every other human. We don’t know where we came from except by “hearsay” from our parents – and we can only accept that by faith. And the only information we have about where we are going is by faith also. But Jesus knew on His own the parameters of His human life because He was God – therefore He could make this statement about being the light of the world.


The second reason Jesus’ witness about being the light of the world was true was because of His perspective in verse 15


You judge according to the flesh; I judge no one.”


Any judgement that you and I make is “according to the flesh” – in other words, our knowledge is limited, because we simply do not have the ability to know all the facts about any given situation. (the reason for “reasonable doubt” in trials.) But Jesus “judges no one” on that basis – His perspective is not limited to the flesh. So that is the second reason Jesus witness about being the light of the world is valid.


The third reason that His promise is valid is in verses 16 through 18, and that is His personal witness.


And yet if I do judge, my judgement is true; for I am not alone, but I am with the Father who sent me. (17) It is also written in your law that the testimony of two men is true (18) I am one who bears witness of myself and the Father who sent me bears witness of me.”


Jesus knew exactly where they were coming from when they said His witness was not true – He knew the Old Testament better than they did.  But now He uses that very doctrine to prove that His witness is true, because He has a second witness – God the Father. It is possible that some of these very men had heard the voice of God the Father saying “this is my beloved Son in whom I am well pleased” at the time of His baptism – if not they had certainly heard about it. So it should be obvious that He had a second witness in His Father.


Finally, in verses 19 and 20 the Pharisees speak again, and this time they reveal their presumption of guilt, aimed at the “scandal” of His human birth.


Then they said to Him, “where is you father?” Jesus answered “You neither know me nor my Father. If you had known me you would have known my Father also” (20) These words Jesus spoke in the treasury, as He taught in the temple, and no one laid hands on Him for His hour had not yet come.


Verse 19 is another of Jesus’ statements that the only way to the Father is knowing the Son. There are many “religious” people in the world today who will not be in heaven because they insist on trying to have a relationship with the Father without knowing the Son. Now you would think a statement like this would be so shocking to these religious leaders that they would attack Him. But verse 20 points out why they didn’t – “His hour had not yet come.” This shows how important the death of Christ on the cross was to God the Father. He protected Him again and again from being put to death for the wrong reasons.


As we wrap this lesson up, let me point out that the Pharisees in this passage demonstrate the difference between trying to come to God on our own terms. The result of taking that approach is that you can’t know the Father or the Son. And instead of having “the light of life” with all of the spiritual and emotional well being that it provides, they were full of bitterness and hatred – and frustration. But that is the pattern of life for those who don’t know “the light of life” – or who, even though they may know Him, don’t “walk in the light as He is in the light.”
































The purpose of these studies is to help people come to know Jesus Christ as their personal Savior. Romans 3:23 says that “All of us have sinned and come short of the glory of God.” “And Romans 6:23 says that “the wages of sin is death, but the gift of God is eternal life.” And John 3:16 says that “God so loved the world that He gave His only begotten Son that whoever believes in him shall not perish, but have everlasting life. If you have never sincerely asked Him to forgive your sins and give you eternal life He will readily do so. Having trusted Him as your savior it is my hope that the lessons will help you grow in grace and bring others to know Him as well. If you would like more information you may contact me at “janicetemple@yahoo.com



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