Matthew 6:22

The lamp of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light. But if thine eye be evil, thy whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great is that darkness!

This is the topic sentence of this section of the Sermon on the Mount, and it comes in the form of a climax. The subject is human duplicity. Christ laid bare the deceitful and double motives which prompt men in their religious actions. Looking back to the beginning of this chapter, note that: (1) men do alms for two motives; (2) they pray for two motives; (3) they fast for two motives; (4) they even SEE DOUBLE! The evil eye is the one that explores every action, regardless of how sacred it is, for the purpose of discovering what base motive might also be served by the doing of it. The corrupting power of this behavior is total; "How great is that darkness!" Any act, even that of prayer or charity, without the proper motivation, becomes sinful. Christ's words in this place truly described the society into which he came as the Visitor from on high. The problem was one of unmitigated hypocrisy, caused by the attempted service of both God and the devil at the same time, or, in another frame of reference, the dual service of God and mammon, or wealth. The Pharisees of that day had corrupted the inner springs of conscience by the duality of their lives. It is certain that many in all generations fall into the same error.