Matt. 6:22 - 23: “The eye is the lamp of the body; so then if your eye is clear, your whole body will be full of light. But if your eye is bad, your whole body will be full of darkness. If then the light that is in you is darkness, how great is the darkness!"
This is a powerful illustration. Almost everything our body does, depends upon our ability to see. It is true that blind people cope wonderfully and develop other faculties to compensate - yet the principle remains. So what Jesus is saying here is that just as our eye affects our whole body, so where we fix our heart, or what we focus on in life will have a huge effect on our journey. Just as our eyes admit light to our body so having a passion for God and His Kingdom will give a godly perspective to our life and we will see things (light) from God’s point of view. This will impact our heart and our inner being. Alternatively, because blindness produces darkness, if we focus on selfish ambition, the various lusts of the flesh and other ungodly traits, that will produce darkness in our lives.
So the point here is that if our eyes are clean and healthy we will see everything as it is, including much natural beauty and the expression of God all around us. But if our eyes are impure and diseased we are going to see a world that is very contrary to the ways of God and we will often be enticed by it. If our perspective is correctly adjusted, then our life is filled with purpose and drive. But if our vision is clouded by false gods of materialism and other such lusts, we will lose the true sense of values and morality and this will guide us down the wrong pathways of life.
However, we should not just consider this passage in a spiritual sense. What we physically look at has a huge effect on our life. Our heart and mind take on board what we see, particularly if we dwell on it. I can never watch horror movies. I saw a couple as a non-Christian adult and they had a terrible effect on me and played on my mind for years. I can’t even watch adds for them. I am so aware of the warning that once you have seen something you can’t unsee it. What we look at, what movies we watch, what we read and what we allow our eyes to feast upon has a huge influence on how we walk. Therefore we should be very guarded at what we allow ourselves to see and what we should look away from.
A good friend of mine makes the following statement - we have two natures within us - a fallen nature and a redeemed nature. Although the redeemed nature is the most powerful (1 John 4:4), the ultimate guiding influence in our life will be dictated by the nature we feed the most. If we feed our fallen nature it will take us in the wrong direction leading to death, but if we feed our redeemed nature it will guide us down the pathway that leads to life.
God bless you