Earlier this month, people around the world were appalled by a video posted online by ISIS in which a member of the terrorist organization beheaded American journalist Steven Sotloff. This past week, Americans were again disgusted by news reports, this time concerning two NFL players—Adrian Peterson, who disciplined his 4-year old son with a switch, leaving deep gashes on sensitive areas of the boy’s body, and Ray Rice, who punched his then-fiancée in the face, knocking her unconscious.

Besides the obvious theme of violence, something else unites these three news stories: all three entered into the news cycle and into the awareness of Americans on account of graphic images infiltrating the public sphere. Regarding both Sotloff’s beheading and the incidents involving NFL players, some have rightly observed that, in a sense, such stories are not news at all. Terrorist organizations like ISIS have been wreaking havoc on the Middle East for years, perpetrating all sorts of atrocities on the people there. Yet only when Americans saw one of their countrymen brutally executed on video did our government vow to take action. Likewise, domestic abuse (and a laundry list of other vices) are nothing new in the NFL. Yet only when Americans saw the photographs of the gashes on the legs of Peterson’s son and the video of Rice’s fiancée crumpling to the elevator floor did people put enough pressure on the NFL to compel officials to impose meaningful penalties on the offending players.

We’ve all heard it said that “seeing is believing,” but seeing is also feeling and acting. Images typically have a greater effect on us than words alone. Advances in the field of neuroscience have given us greater insight into this connection between visualization and affect. The way the human mind works, our experiences register in our consciousness in the form of mental images, which are always charged with feeling—pleasure, pain, elation, melancholy, approval, and disgust. Abstract thought, too, is rooted in sensation and imagination, but, because abstractions are more remote from our immediate experiences, they do not carry the same emotional charge and so do not impact us as strongly as do the sensations and images themselves. The result in everyday terms is that, while most of have long understood at an intellectual level that terrorism is ravaging the Middle East, that intellectual understanding never got our blood boiling the way that video did on September 9.

As philosopher and theologian Marianne Sawicki has observed, “The advertising and public-relations industries are founded on the conviction that the symbol, the image, the story are the most powerful and effective elements in the modern world.” People who make a living by influencing the actions of others know that immersing people in images is the most sure-fire way to get them to buy a certain product or vote for a particular candidate. This is why corporations pay billions to slap their logos on every available flat surface. This is why you can no longer check posts on your wall or read an article online without advertising images crowding into every spare inch of your visual field. This is why images of the human body on TV shows, movies, and advertisements are increasingly revealing. The more graphic the image, the more immediately related to primal urges and emotions, the more quickly it grabs our attention.

Pointing out gratuitous violence and sexualized images in the entertainment and advertising industries is no more novel than reports of violence in the Middle East or of unlawful behavior in the NFL. Every time a new, more violent video game hits the market or a movie crosses yet another line of decency, cries rise up in protest from certain sectors of the public. Yet, for all the protest, the offending images continue to proliferate. What are we to make of this inexorable march of immodesty? Are we to conclude that the battle for our imaginations is already lost?

I believe that the Christian tradition offers us hope in this regard. Human beings’ struggle with pernicious images is a prominent theme in the Bible. Jesus himself acknowledged this perennial struggle, observing, “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 unhealthy, your whole body will be full of darkness” (Mt 6:22-23). Jesus’ words clearly advise us to care for our vision. The million-dollar question here is, how do we ensure that our vision is healthy? Jesus is not talking about annual visits to the optometrist or keeping a bottle of Visine handy. Rather, he is talking about filling our imaginations with the right kind of images. More specifically, he is calling us to set our sights on him, who is “the image of the invisible God” (Col 1:15), and to reflect that image ourselves.

To be sure, setting our sights on the right images is easier said than done in an age of ubiquitous billboards and smartphones. The reality today is that, if we passively allow ourselves to be formed by whatever images the culture projects at us, our imaginations will be dark indeed. For that reason, we need to be intentional about the formation of our own imaginations. Like the ancient Israelites, we ought to eschew certain images and seek out others. For example, we have the ability to be discerning about what movies and TV programs we watch and how long our eyes linger on violent or sexualized images when they appear before us.

One might point out that that the Israelites had it easy insofar as they had far fewer unhealthy images to worry about. The occasional golden calf doesn’t seem like so big a deal to the modern American who can’t turn left or right without seeing the golden arches. While this is true enough, today we have the advantage of being able to create a healthy visual environment for ourselves with relative ease. We have a far greater say over the decorations adorning our homes, not to mention the images we display on our electronic devices. We have at our disposal the means of finding images that inspire us and make us want to be holier, more loving people and of keeping them before our eyes. It’s as easy as taping a picture to a desk or locker or changing the images on our computer desktop or phone display.

With all that modern science can tell us about how the human brain works, we know today that the images we internalize are constitutive of how we see the world and conduct ourselves within it. To a great degree, it is within our power to shape our own imaginations and, through them, our very moral character. As recent news stories have made clear, there is plenty of darkness in the world. We desperately need people who can shine a bit of light. When the first step is as simple as changing the image on your phone display, why not be the one to shine?