What are you seeing? Lightness or Darkness? Matthew 6:22-23
Matthew 5:14-16 says that you are the light of the world. That light Matthew is talking about is the Word of God inside of you. In Matthew 6:22, he narrows the light from being the word of God inside of you to what you see and focus on in every day life.
The eye needs light to be able to see and read. The word of God comes into us through reading and hearing. In many cases seeing can be more powerful than hearing. We get our first impressions of another person, place, or thing through site. Whether it is seeing someone in person through a brochure, or an advertisement, that first impression is the most important.
It is so important that some sales people feel if they did not make a good first impression, they blew it already. It is the first impression that attracts you to what you are looking at, or repels you. If you are of God and have the Holy Spirit in you guiding you, you will tend to be drawn towards what first appears to be a godly person, place, or thing in an ad. Likewise you would be repelled to what appears to be an ungodly person, an ungodly place, or ungodly things.
Even if you have God inside of you, there are times when the ungodly things draws your eye towards it. The eye giving you a tempting visual can be very powerful in creating lusts. For you to lust for something, you need to either hear about it or see it first. A visual of a beautiful woman or man in a skimpy swimsuit can be more powerful than hearing about a woman or man in a skimpy swimsuit. This leaves the door open to the devil to create a lustful thought in you. Just looking at something can create thoughts about doing something that you normally would not do. Those thoughts can later become action, if we are not careful.
If thy eye be single, thy whole body shall be full of light. Single goes along with the use of walking along the straight and narrow path, that there is only one way to God which is through Jesus Christ. God is not double minded that he shall not say one thing and then do something else. For the eye to be single is to keep your site on Godly things and people, and not go out of your way to look at something that is against God. If you see something not of God, do not focus on it.
The above also makes sense when compared to the next verse, "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!" Matthew does not say if thine eye be double though. It is as if once your eye focuses on evil there are so many ways to look that he could not put a number on it. Wide is the path that leads to destruction.
Once the eye is focused on evil, the light becomes darkness, because the word of God in you is being covered and becoming dim. If the evil continues, it will grow until the light is out, and total darkness of evil takes place of the light of the word of God in you.
What are you looking at, and letting into your life? Things of God? Or things of the devil?