In Lk 11:33-36, Jesus used the illustration of a lighted candle to teach his disciples about seeing him and having their whole bodies full of light and having no part dark.

In the context of this passage, Jesus had just rebuked this evil generation for seeking a sign, Lk 11:29-32.  They were looking for a sign when the very light of the world, who is greater than Jonas and Solomon, was standing right there in front of them.

Jesus illustrated this phenomenon by referring to a lighted candle.  Candles are lit so that all may see the light when they come in the room.  They are not lit to be hidden in a secret place or under a shade.  

Likewise, Jesus, the light of the world, came to give light to every man.  He didn’t appear in secret, nor was he hidden from their view.  The trouble with the people who didn’t see him, therefore, was not a problem with Jesus’s light, but rather with their eyes.  

The light of the body is the eye.  This “light” is the medium through which light is admitted.  So, with their eyes, the light emanating from Jesus should have been admitted to their bodies.  However, for many of them, it wasn’t, because their eye wasn’t “single”.

So, Jesus taught them about the necessity for their eye to be “single”.  A single eye is an eye that is exclusively attentive and pure and incorrupt.  Contrast the single eye, in v.34, with the “evil” eye.  A single eye is not evil.

When the eye is single, that is, exclusively attentive on Jesus Christ the light, the whole body is full of light.  By contrast, when the eye is evil, that is, corrupt and not exclusively attentive on Jesus, the whole body is full of darkness.  

This is why Jesus warned them to “take heed therefore that the light which is in thee be not darkness”, v.35.  Darkness is not the absence of light but rather a dark light, Is 45:7, comparable in this illustration to the darkness of the devil and his kingdom, 2 Cor 4:3-6, Eph 6:12.

Jesus concluded his illustration with an admonition to have the whole body full of light having no part dark, v.36.  He said, “If thy whole body therefore be full of light having no part dark, the whole shall be full of light as when the bright shining of a candle doth give thee light”.

He brought this instruction all the way back around to the illustration he had given them about the lighted candle.  The bright shining of the candle will give thee light when your eye is single and your body has no part dark.

For us, this illustration is instructive, as it was for them.  Many Christians today are not full of light, having no part dark.  Their eyes aren’t single.  They look to other sources besides the light of God, Jesus Christ, and the words of God for their light.  Therefore, their bodies are not “full of light, having no part dark”.  Rather, there is darkness because they are not seeing what God wants them to see the way that God wants them to see it.

We must be careful, as God’s children, to keep our eyes single.  We must take heed to keep dark light from entering through our eyes.  We must have no part dark.  We must keep our eyes on God, who is light, Jesus, who is the light of the world, and the Bible, which is a light to our path.

For another sermon on the eye, see The Seeing Eye.