What we feed our eyes will eventually rule our hearts. And I’m not just talking about pornography.

Jesus says, “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!” (Matthew 6:22–23; Luke 11:34).

Yes, our eyes will be drawn to what our hearts desire, but they also often hold sway. Our eyes are not neutral. They influence and even drive our hearts. If we feed them what is true, and right, and pure, and lovely, and admirable, our eyes can grow our faith, heighten our love, and intensify our happiness. But where the eyes wander, the heart quickly follows — and falls. How many of us leave our eyes on too long a leash?

For some, tragically, it is pornography. For others, it’s something less salacious, like sports scores or news headlines. For others, Instagram or Facebook. For still others, it’s Amazon or Target, YouTube or Netflix. Just because something isn’t inherently bad, doesn’t mean it can’t fill our eyes so full as to crowd out the one who matters most. That’s what darkened eyes are: eyes so full of something other than Christ that they can no longer see him and enjoy him.

Lamp of the Body

When Moses warned Israel about idolatry, he stared directly into their eyes:

“Watch yourselves very carefully. . . . Beware lest you act corruptly by making a carved image for yourselves, in the form of any figure, the likeness of male or female, the likeness of any animal that is on the earth, the likeness of any winged bird that flies in the air, the likeness of anything that creeps on the ground, the likeness of any fish that is in the water under the earth. And beware lest you raise your eyes to heaven, and when you see the sun and the moon and the stars, all the host of heaven, you be drawn away and bow down to them and serve them.” (Deuteronomy 4:15–19)

The eye is the lamp of the body, he said to God’s people, and if you allow yours to lust after the things you have made, or even after the wonders God has made — your eyes will lead your heart astray and eventually destroy you.

Moses didn’t mention sexually explicit images. No, he knew the people would be tempted to worship even the good in creation — animals, birds, and fish; sun, moon, and stars — the wonders God had placed all around them. The wonder of wonders is that we often end up worshiping the wonder and not the Creator.

What Your Eyes Say

How do our eyes lead our hearts away from God? When Jesus says, “The eye is the lamp of the body,” he’s in the middle of a word about treasure. Three verses earlier, he says, “Do not lay up for yourselves treasures on earth” (Matthew 6:19). And then two verses later, he says, “No one can serve two masters. . . . You cannot serve God and money” (Matthew 6:24). Our eyes will always be drawn to what we treasure. But more than that, they play a role in what we treasure. If our eyes are sick, we’ll inevitably have heart trouble.

And money, as Jesus teaches, carves as many images as anything today. If we’re not content to have him, we’ll fall in love with whatever else we can have (or buy).

If we have little appetite for Christ, and a voracious craving for sports, our treasure is free of charge at ESPN. If Christ cannot keep our attention, but we hunt and shop for hours on Amazon, our treasure should arrive in two business days or less. If we lack ambition to know Christ and carry out his mission, but we work hard to advance our career and build our retirement fund, we’ll finally receive our treasure as our time on earth expires. If time with Christ is the first thing we surrender when we’re busy, but we never miss a meal or our favorite television show, we have treasure, but it’s not him.

And if it’s not him, every other good goes dark.

Eyes Full of Adultery

The apostle Peter says that the wicked “have eyes full of adultery, insatiable for sin” (2 Peter 2:14). They have looked at Christ and found him unlovely, so they lust after something else (often someone else). “The light has come into the world, and people loved the darkness rather than the light” (John 3:19). We were given the option between the fullest loveliness and the weakest pleasures, and we loved the latter. That is wicked — and pitiful. Eyes full of adultery have chosen cyanide over ecstasy.

Those were our eyes, but we were washed, we were sanctified, we were justified in the name of the Lord Jesus Christ and by the Spirit of our God (1 Corinthians 6:11). We received laser eye surgery from the one who invented retinas. He stooped down and, with compassion, spit in our eyes to heal those who had spit on his glory (Mark 8:23).

And if he has made our eyes healthy, our whole body will be full of light.

Watch What You Watch

If you have let your eyes get out of shape, it’s not too late to learn to guard them and keep them healthy. First, fill your eyes with the words of God. If you want to make sure there is room for God, let him in first. Before you’re exposed to everything else you will see today, decide to see him. Let a fresh vision of him in his word be the day’s first wonder, the sun that eclipses and illumines every other beauty. Steep your soul in Scripture long enough that you begin to see God in all the other wonders around you.

Second, compare your prayer life with your screen life — which will humble almost anyone alive today. When we set the time we spend on our phones, or in front of televisions, next to the time we spend on our knees, what do we learn about our eyes and our hearts? The decisive concern here is not with the time spent, but with the commitment, passion, and affection we exert. Where do we run for rest and pleasure? Too many of us have not closed our eyes and bowed our heads enough to find the rest and pleasure we think we’re getting from a screen.

Third, do not train your eyes to overlook ungodliness or to tolerate immodesty. Neither will happen passively or accidentally. Godliness will require vigilance in what we watch, especially in a society aggressively marketing everything else. Some of us have drawn the lines to forbid the worst, while allowing an endless stream of sexually suggestive or immodest scenes into our eyes. We have also learned to ignore (and even indulge) the gods in our entertainment, instead of discerning and exposing them. This is not a call not to watch, but to watch what we watch, lest we raise our eyes to deceitful desires, are drawn away, and bow down and serve them.

Eyes Wide Open

The warnings from Moses and Jesus are not meant to limit what we see, but to focus and expand what we see. They want us to see more, to have healthy eyes wide open for God. Steve DeWitt writes,

The beauties of this world whisper to our souls that there is someone ultimate. But the ultimate is never found in the wonderland of creation. We keep looking and longing for the beauty behind the beauty, the One who will satisfy the cravings of our soul. This explains why the drug addict keeps shooting up and the porn addict keeps looking and the materialist keeps buying and the thrill-seeker keeps jumping. On the other side of one thrill is the constant need for another. (Eyes Wide Open, 71)

As you walk through the wonderland of God’s creation, watch your eyes carefully. These thrills are whispers of Wonder, mere shadows of Light. They’re meant to make us more in awe of Christ, and to prepare us to spend eternity looking to him. “He is coming with the clouds, and every eye will see him” (Revelation 1:7). We all will see him. How we use our eyes today will determine whether he is lovely when we do.