I am going to suggest that Jesus is giving us a general recipe for doing life with joy and optimism, as contrasted with a recipe for depression. Let’s look again at verses 22 and 23. “The eye is the lamp of the body. If your eyes are good, your whole body will be full of light. But if your eyes are bad, your whole body will be full of darkness. If then the light within you is darkness, how great is that darkness!”
Here’s my spin: Your worldview perspective determines the quality of your life. If you are able to recognize with your internal eyes the greatness, goodness, majesty, and grace of the awesome God of the Bible, then every other part of your life will be invigorated by that view. But if your perspective sees no order or design or purpose, the result can only be self-centeredness, confusion, and meaninglessness, which is an appropriate way to define depression.
Does it require any difficult or complicated reasoning to figure out which approach is superior? I don’t think so!
I don’t want to sign off before directing attention to 6:33 which I believe is the bottom-line key to this “Sermon on the Mount” (Matthew 5-7). Indeed it is key to doing life. “But seek first his kingdom and his righteousness, and all these things will be given to you as well.”