The eye is the lamp of the body. If then your eye is healthy, your whole body will be full of light. 23 But if your eye is diseased, your whole body will be full of darkness. If then the light in you is darkness, how great is the darkness!
Note: any Bible reference containing only a chapter number and verse number is understood to be in the Gospel of Matthew.
The focus of attention tells all
Scientists use a whole array of instruments to see what is visually unseen. Sonar does the job in water, ground-penetrating radar reveals objects underground, and ultrasound can show a tumor. But how can we illuminate the spiritual contours of the human heart?
In a context (6:19-34) that plainly deals with material possessions, Matthew 6:22-23 is challenging. The big question seems to be: in what sense is the eye the lamp of the body? I will answer that question next.
Of all the things the eye could see, it focuses attention on what the heart wants. The healthy eye gives attention to the things of God and his kingdom, and that fills the disciple of Jesus with light. But the diseased eye (6:23) prioritizes its vision for the things offered by the world, especially money and possessions or sex. The diseased eye incarnates the tastes of the diseased heart, a heart filled with darkness.
Having given the basic interpretation, we will now examine some of the details. Jesus states the basic principle first: “The eye is the lamp of the body” (6:22a). Using the lamp as a metaphor for the eye is not self-explanatory. A lamp provides light for the constructive activities of life.
But the eye is not free to look anywhere it likes; it looks where the heart directs it. So, the images admitted by the eye are a commentary on the interests of the heart. To focus on the positive, we will look closely at the meaning of the word translated healthy (6:22). The Greek adjective means: “pertaining to being motivated by singleness of purpose so as to be open and aboveboard, single, without guile, sincere, straightforward.”
Since Jesus has just commanded that his disciples store up treasures in heaven (6:20), it is clear that Jesus has in mind a singleness of purpose that will animate his disciples to serve the kingdom of heaven. He will say that explicitly in Matt. 6:33, when he says, But above all pursue his kingdom and righteousness, and all these things will be given to you as well.
But something else is going on here as well. Jesus has previously commanded his disciples to be generous toward others in need (5:42), so in this context about material possessions it would not be surprising to see that theme recur. Sure enough, a secondary meaning of the word translated healthy (6:22) is generous. This dual meaning for the healthy eye, expressing both single-minded and generous, will help us understand what the diseased (6:23) eye means.
The diseased eye causes inner darkness primarily because it is not focused on the kingdom of God. But David Turner explains that a secondary meaning involves greed and stinginess. In other words, the person with a diseased eye turns away from his brother in need and thus shows he is no disciple of Jesus.
This complex wordplay would have been much more obvious to those listening to Jesus because these alternate meanings were well-known in those times. It is obvious, however, that the way we look at the world tells a great deal about what we are like inwardly.
Measuring spiritual heart health
Prejudices, assumptions, blind faith in certain unbiblical ideas, and false ways of determining truth all play a role in blinding us to what God wants us to see. The eye that sees like Jesus will not look on the world with greed but will see others in need and meet those needs. In doing so, the nature of the heart is revealed.
Apparently, the best way to be sure that material possessions do not come between you and God is to give them away to meet the needs of others. Such a person is a visionary for God!
Copyright 2011 by Barry Applewhite, Plano, Texas. All rights reserved worldwide. Derived from material created for Christ Fellowship, McKinney, Texas. Used by permission.
 BDAG-3, haplous, straightforward, q.v.
 David L. Turner, Matthew, Baker Exegetical Commentary on the New Testament (Grand Rapids, Baker Academic, 2008) 262.