“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 lamp of the body is the eye. If therefore your eye is good, your whole body will be full of light. But if your eye is bad, your whole body will be full of darkness. If therefore the light that is in you is darkness, how great is that darkness!
"No one can serve two masters; for either he will hate the one and love the other, or else he will be loyal to the one and despise the other. You cannot serve God and mammon."
- Matthew 6:19-24
We are reading through the Sermon on the Mount (Matthew chs. 5-7). In the previous reading, Jesus taught, "And when you pray, do not use vain repetitions as the heathen do. For they think that they will be heard for their many words. Therefore do not be like them. For your Father knows the things you have need of before you ask Him. In this manner, therefore, pray: Our Father in heaven, hallowed be Your name. Your kingdom come. Your will be done on earth as it is in heaven. Give us this day our daily bread. And forgive us our debts, as we forgive our debtors. And do not lead us into temptation, but deliver us from the evil one. For Yours is the kingdom and the power and the glory forever. Amen. For if you forgive men their trespasses, your heavenly Father will also forgive you. But if you do not forgive men their trespasses, neither will your Father forgive your trespasses."
“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." My study bible notes here: "By attaching themselves to treasures on earth, people cut themselves off from heavenly treasures. They become slaves to earthly things rather than free in Christ. The heart of discipleship lies in (1) disentangling ourselves from the chains of earthly things, and (2) attaching ourselves to God, the true treasure."
"The lamp of the body is the eye. If therefore your eye is good, your whole body will be full of light. But if your eye is bad, your whole body will be full of darkness. If therefore the light that is in you is darkness, how great is that darkness!" A note reads: "The mind (Gr. nous) is the spiritual eye of the soul; it illuminates the inner man and governs the will. Keeping the mind wholesome and pure is fundamental to the Christian life."
"No one can serve two masters; for either he will hate the one and love the other, or else he will be loyal to the one and despise the other. You cannot serve God and mammon." My study bible says, "As slaves serving two masters, people attempt to maintain an attachment to both earthly and heavenly things. But this is impossible, since both demand full allegiance. Jesus calls mammon ('riches') a master not because wealth is evil by nature, but because of the control it has over people."
Jesus is teaching us something here about making our eye single, in the sense that we cover ourselves with the fullness of the light that we seek, and we are as single-minded about it as we can be. (See 5:29.) Jesus is also speaking here about faith, what it is exactly that illumines who we are, gives us good sight, true light by which to see and to dispel every darkness. And He gives us also a meaning to the lack of faith. We are worshiping something else. There is not merely, in Christ's vision here, faith in God, or a lack of it. No, we know that elsewhere a man who is loved by Jesus and set for us as an example, will say, "Lord, I believe; help my unbelief!" It's not "unbelief" that is the real thief here altogether; our faith doesn't mean we don't have doubts. What Jesus presents here is the lack of ability to make our eye single, that is, full of the light of faith, because we are torn between worshiping two things which are incompatible. You cannot serve God and mammon, or riches, pretty much serves it up to us and puts it the way we have to look at it. When we put our faith in the material, in the pursuit of wealth first, then we are acting in a way entirely contradictory to faith in God. I believe that we are creatures built for worship. If we don't worship God we're going to put our faith in something else, something else is going to come first. We may not even be aware of what idol we're worshiping! We may never have the self-knowledge to understand where precisely all our efforts are going, what we truly hold dear. Self-knowledge like this is yet another product of our faith in Christ. His faith is that which gives us self-understanding, enlightens for us all things, illumines the dark corners we'd never dream of looking at on our own. His faith is that which moves mountains and makes possible all things (even the conversion of a rich man who is over-attached to wealth - see 19:23-30). Let us note that in the next reading, Jesus will teach us about our faith, and give us a promise about what we are to seek first, and what will be added unto us. He's not scathingly tossing out all things that give us comfort or beauty or happiness, far to the contrary. But He does teach us about where we set our heart, what must fully illumine our own sight -- and He is unflinching and uncompromising when He teaches us how can we get in our own way.