The eye is the lamp of the body. If your eyes are healthy, your whole body will be full of light. But if your eyes are unhealthy, your whole body will be full of darkness. If then the light within you is darkness, how great is that darkness! —Matthew 6:22–23

One of the curious things for anybody trying to understand the passage is this illustration about the eye. It says, “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.” Now what that means is simple. There’s light in this room, and if your eye works, if it takes the light in, you will by the light be able to move your body through the room. You’ll see where the aisle is, and you won’t stumble or fall. All this is saying is if your eye isn’t working, even though there’s light around the rest of your body, your whole body is, in a sense, in the darkness. If your eye is not working, there’s a sense in which no other part of your body can see or take the light in. So if your eye is not working, your whole body is in darkness, whether or not the whole room is flooded with light.

In Luke 11 Jesus uses the same illustration, that the eye is the lamp of the body, that if your eye is dark, your whole body is dark. He also talks about money again. It’s connected. When you get into Luke 12, after he talks about the eye and the lamp, he says: so watch out for greed.

He’s saying that materialism is an inordinate desire or dependence on money and material things that has the peculiar effect of blinding you spiritually, of distorting the way you see things. It has power over the way you see everything. Let me give you some examples. First of all, materialism has the power to blind you to materialism.

Some years ago, my wife, Kathy, noticed I was doing a series of monthly morning breakfasts on the seven deadly sins. The seven deadly sins include lust, pride, envy, anger, and so forth. And, of course, one of the seven deadly sins is greed. Kathy asked, “Are they advertising these things?” I said, “Yes, they’re advertising.” She said, “So they’ll know the month you’re speaking on greed?” I said, “Right.” She said, “Watch, the attendance is going to drop. They’re not going to come out to hear about greed.” And she was right. It was the least attended of all of them.

Why? It’s not that they were hostile. It’s not that people said, “That’s a terrible idea. I don’t want to hear about greed.” No. Everybody was just so sure it wasn’t true of them.

Greed is different than other sins. This is why Jesus says this is an eye sin. This darkens your eye spiritually. Jesus did not say to anybody, “Watch out, you might be committing adultery.” If you’re committing adultery; you know you’re committing adultery. You don’t say, “Oh, you’re not my wife!” It doesn’t happen. But Jesus has to say, Watch out, you might be greedy. Greed hides itself. It blinds you in a way that adultery doesn’t. Over the years as a pastor, I’ve had people come in to talk to me about sins, but I don’t remember anybody coming to me to confess the sin of greed.

Who are you accountable to? What Christians have you gotten together with and said, “Let’s talk about how we’re spending our money … how much we’re giving away, how much we’re keeping, what we’re doing”?

Jesus is saying: You don’t ask. You don’t consider the possibility that you’re greedy. You don’t think you are. You say, “Me? Greedy?” You think of rich people. You think of people that spend tons. Most of you even have a relative who’s more extravagant with money than you are. That’s all it takes. All you have to do is know somebody who’s really greedy, and you won’t think you’re greedy. You wouldn’t even consider the possibility that you’re materialistic.

If you say, “This is not a problem of mine,” that’s a very bad sign. A symptom of this sin is thinking, I’m sure it’s not true of me. Jesus is saying watch out. This is a sin of the eye. It darkens your eye.

For example, materialism has the power to get you to choose a job, not one that you love, not one that you’re good at, not one that helps people, but one that makes you money. You do it because it will get you to a certain status in life. You choose the job on the basis of that. For five to ten years the adrenaline can keep you going, but after a while you find yourself empty inside. Why did you choose the job? Your eye was dark.

Not only can materialism blind you as you choose your job, but it can blind you in the conduct of your job. For example, many companies are making money, but they’re hurting neighborhoods. They’re hurting towns. They’re hurting people. There are all sorts of people in the company, and what are they doing? Are they saying, “Aha! In order to make money I will ruin the environment of that little town”? No, they’re not doing that. They’re not asking. They don’t want to go there. They don’t want to ask hard questions: Are the things my company is doing helping people or hurting people? Is it helping the town or is it hurting the town? Is it helping the neighborhood or is it hurting? You don’t want to know. That’s the blindness. That’s what Jesus is talking about. Greed doesn’t go, “Aha! I am gouging the poor!” No, but are you asking whether your company is? You need to ask that.

Materialism also keeps you from asking hard questions about your lifestyle. One of the problems is the kinds of people you come into contact with. Sometimes your friends are making ten times the money you are. You might have a good job, but here’s a person making ten times, fifty times what you’re making. Don’t forget, the person you think is rich is hanging out with people who make ten times more than they do every year. Therefore, nobody ever feels rich.

You don’t ask these questions: Do I really need to spend as much money on this? Do I need to be putting this much money into my apartment? Do I need to be spending this much money on clothes? Immediately you think of people who spend much more, so you don’t ask the questions. You don’t say: Aren’t there ways I could be giving more of my money to the church, to the poor, to my friends, to the neighbors? Aren’t there ways I could be more radically generous if I made this and that and that change? You don’t want to ask. You don’t want to think.

In 1635, a guy named Robert Cain was a member of the First Congregational Church of Boston. He was doing well as a businessman, but his elders disciplined him for the sin of greed. Now how did they do that? It was because he was selling his product at a six percent profit, and the church had decided three or four years before that Christians were only allowed to sell their wares at a four percent profit. So when they found out he was doing six percent, they disciplined him for the sin of greed.

Some of you are saying, “Where does it say in the Bible four percent? What are you talking about?” These church elders knew that when you’re committing adultery you know you’re committing adultery, but when you’re being greedy you never know. So they sat down as Christians and said: Jesus talks about money all the time. He’s constantly saying watch out for greed. He’s always saying give your money away. He’s always saying don’t spend all your money on yourself. So some business practices must be greedy. Some lifestyles have to be greedy. How are we going to know? As a Christian community, let’s sit down and decide, at our time in our place in this spot, what is a greedy lifestyle and what are greedy business practices. So by consensus they decided on some rules and decided to hold each other accountable. It was consensual. And of course Robert Cain knew about it, but he tried to move past it.

I am not saying by any means that today, in our economy, you could come up with a nice, simple rule of thumb. But here’s the point: Who are you accountable to? What Christians have you gotten together with and said, “Let’s talk about how we’re spending our money on each other, on ourselves, how much we’re giving away, how much we’re keeping, what we’re doing”? You have to talk about this with somebody. You’ve got to have some standards. And you can’t trust yourself. That’s the principle. You cannot trust yourself to decide this.

Source: Timothy Keller, “Treasure versus Money,” sermon preached May 2, 1999, published in Preaching Today (August 2005).