"No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money. “Therefore I tell you, do not be anxious about your life, what you will eat or what you will drink, nor about your body, what you will put on. . . ."
However if you go back to verse 19 and continue to verse 25, it becomes more clear.
"Do not lay up for yourselves treasures on earth, where moth and rust destroy and where thieves break in and steal, but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. For where your treasure is, there your heart will be also.
"The eye is the lamp of the body. So, if your eye is healthy, 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 in you is darkness, how great is the darkness!
"No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money. “Therefore I tell you, do not be anxious about your life, what you will eat or what you will drink, nor about your body, what you will put on."
The issue here is that our eyes are bad. That we don't receive the Word, which is a lamp to our feet and a light to our path. We don't invest in the things that have an eternal ROI. And because our eyes are bad, we see only the bad things, the evil things that surround us. We come home from a day at work, and we talk about the things that went wrong. Even our best days, when almost everything goes according to plan and where almost everything comes off without a hitch, we come home and dwell on and stew over the few things that went wrong. We fixate on the problems, which breeds anxiety and worry. Why is it that we wonder and fixate on how so much goes wrong? Why do we not marvel instead at just how much goes right?
We have a vision problem. Our sight is darkened. Our conscience is defiled and tainted. We don't see things as the Lord reveals them to us in His Word. We only see the gunk and the grime, and we fixate on it, as though we were looking through a windshield soiled with bugs and dirt and mud unable to see past it all to the light of day to the clear reality beyond all the mess.
And so our Lord asks us what there is to worry about? Your heavenly Father has sent light into the world. He set the lights by His Word in the sky in the beginning. He has sent it now in the flesh. The light is among us. The Lord provides. He provides everything we need for this body and life. He has given all that we need for this body and eternal life. He cleanses your conscience with water and word, clothes you with His body and blood, His righteousness. The Kingdom is yours. For you have the King to whom they belong. His throne is still the cross. The victim is still the victor. The Lord reigns. He reigns forever, provides forever, lives forever. And so shall you. What is there left to be anxious about?