It would be ludicrous to light a lamp or a candle in order to hide it away in a secret place or place it under a covering that doesn’t offer those in the room the benefit of its light. If we are to understand what Jesus says in Luke at this point, we must look elsewhere to define the words used in the parables of Luke 11:33-36). Jesus claimed he was the Light of the world (John 9:5). He had come into the world (John 1:9) and shone out of darkness (John 1:5). Clearly, darkness is powerless to extinguish light, and Jesus is the Light through whom men, who live in darkness, believe (or see – John 1:7). Jesus’ proper role in the metaphor of the Parable of the Lamp or Candle (Luke 11:33) was to illuminate the house (Israel).
When properly used, light is placed in a location that could illuminate the whole house, and in Jesus parable this would be on a lamp-stand or candlestick (Luke 11:33; cf. Exodus 25:31-35; Zechariah 4:2). In the larger context, however, the people of God, represented by the seven lamp-stands in the Temple of God (cf. Revelation 1:12-13, 20), were supposed to let the Light of God be seen in their lives, in their good works (cf. Matthew 5:16). Jesus claimed the Jewish leaders were seeking to extinguish or at least hide the Light (Christ), probably because they were afraid the Romans would come and destroy their nation and its Temple (cf. John 11:47-48).
The light in Jesus next parable (Luke 11:34-36) is described as the eye (Luke 11:34), which sheds light throughout the body. The eye admits light into the body. Through it the body is able to understand its surroundings and comprehend truth. Often our attitude will affect what we understand as truth. Anyone who is bigoted, for example, will not receive truth from the one he hates. On the other hand, anyone who is overly impressed with a man will believe anything his hero will say, despite truth to the contrary. If the light of the body is the eye, then the eye’s attitude / health will determine whether the body is illuminated or lay in darkness. To illuminate the body in Luke’s context would be to fill it with truth, i.e. the Gospel. However, to reject the truth / Gospel would be to reject Jesus and fill the body with darkness, which means to be spiritually blind.
If the eye is evil (not working properly, spiritually blind), it will be unable to give light to the rest of the body. According to 1Corinthians 12:27, the body represents the people of God. In the context of Luke’s narrative, it is the Jewish nation. The eyes of the body (1Corinthians 12:16) are the leaders and / or teachers of the nation, especially the leadership at Jerusalem (cf. Numbers 10:31; Job 29:15; Psalm 32:8).
Jesus told his listeners to beware that their light isn’t darkness. That is, beware that the doctrine they believe isn’t full of error. If the eyes of the body are evil, i.e. if their perception of light (truth) is off the mark, they would be trusting in something that couldn’t help them. Jesus performed a miracle by casting out the dumb spirit from the mute man (Luke 11:14), yet, all the Jewish leaders were able to see was a power or authority that they couldn’t understand or control, so they then labeled it evil (Luke 11:15). Jesus concluded, therefore, that the eyes of the Jews were diseased. That is, the leaders of the Jews were blind guides (cf. Matthew 23:16, 24).
The immediate context of Jesus’ words was that he wanted the Jews to step back and consider the gravity of the position they had taken (Luke 11:35). In the larger context he wanted the Jews to follow him and mark those who took the lead in doing so, because in them the Jews would have an example to follow (Philippians 3:17). Those among them who were spiritual and believed could help their friends who were overcome with unbelief and skepticism, provided they did so in a spirit of meekness (cf. Galatians 6:1). In other words, Jesus was pointing out that it wasn’t too late to repent and gather themselves behind him (cf. Luke 11:23).
If, therefore, the whole body is full of light, it is because Jesus, who is the Light of the world (John 9:5), is held in good esteem by the leaders (eyes) of the body. When the leaders honor Christ (John 1:5, 7, 9) by putting him in his proper place in their own lives, then what they tell (teach) the nation will exhort the people to exalt Jesus in their lives as well (Luke 11:34, 36).