“Everyone is in a process of spiritual formation. We are being shaped into either the wholeness of the image of Christ or a horribly destructive caricature of that image—destructive not only to ourselves but also to others, for we inflict our brokenness upon them . . . The direction of our spiritual growth infuses all we do with intimations of either Life or Death.”

—Robert Mulholland Jr., Invitation to a Journey

Trees are interesting, aren’t they? Here in California, I’m surrounded by trees as old as time. Sequoia National Forest, filled with trees up to 2,700 years old, is five hours away. My own home sits in the shade of a redwood tree that is near a hundred feet tall. Trees can be many things. They are strong and steady, a calming presence in an ever-changing and chaotic world. They offer us shade. And from their strength we build structures as tall as the sky.

It’s easy to think of trees as an immovable presence in this world, but humankind, in all our wisdom, learned that even the strength of trees can be manipulated for our amusement. Search “tree shaping” and you’ll come across images of trees that have been shaped to look like pretzels, people, houses, and chairs. If a person is patient, steady, and wise enough to use the right tools, they can turn an ordinary tree into something whimsical.

The travel guide Atlas Obscura tells us more: “All tree shapers seem to discover the same basic principle: To train trees, it helps to mold them to existing structures. In Indonesia and northeastern India, the roots of banyan and rubber trees have been wrapped around bamboo frames to form root bridges that can withstand the fierce monsoon. In Europe, gardeners developed a technique called espalier, which involves training trees on a plane so they grow flat. They can then be guided into formal patterns and even words.”

Tree shaping makes me think of our hearts. More specifically, it makes me think of all the ways our hearts are shaped by the things we bind them to. For some, the heart is bound tightly to a person: a spouse, a child, a girlfriend or boyfriend. For others, the heart is bound to a dream: something that is hoped for.

It may also be that our hearts have been bound to regret: a poor decision made in a moment of weakness that has remained a boulder on our back. It might be politics: feeling a deep belief that one’s preferred political party is the only true Christian party. It might be anger or resentment felt toward an enemy or a friend who betrayed us. It could be a relentless drive to consume, to collect more and more in order to keep up. It could be the constant outrage we feel about a world that’s being torn apart at the seams.

The character of our love shapes the character of our heart. The object of our attachment influences the character of our hearts.

I believe this is why Jesus so often talked about masters and the importance of choosing wisely. Our Creator knows our hearts have a way of becoming attached to people and experiences and that those attachments have a transformative impact on our lives. Much like a tree under the purposeful plan and skill of a tree shaper, our hearts and lives are steadily formed by the contours of that which guides us. The character of our love shapes the character of our heart. The object of our attachment influences the character of our hearts.

This isn’t, however, only a biblical concept. Science affirms it too. Studies show that our minds are actually shaped by the things we do and the people with whom we associate. We become like what we love. If we watch hyper-partisan news, we’ll be more likely to isolate ourselves from and demonize those with alternative viewpoints. If we refuse to forgive, we’ll have higher blood pressure and a weaker immune system.

The idea of having a single-minded purpose and focus for our lives on God has a name, of course: holiness. The denomination in which I serve talks quite a lot about the holy life. We believe God calls the church—both individually and corporately—to a life of holiness. We aren’t simply ascribing to a set of beliefs. Rather, we believe faith has a significant impact on the shape of the heart.

Yes, holiness is impactful, but it’s also intentional. There are no haphazardly formed saints. Perfect love (what we call holiness), while submitted to “in a moment,” takes the whole of our lives to grow into its fullest form. This is why, for centuries, our spiritual ancestors followed certain “rules of life.” The early fathers and mothers of our faith understood the chaotic nature of the unformed soul, and their teaching stresses the necessity of intentionally binding ourselves to the tradition and practices of our faith.

The call of the Christian journey—the call of holiness—is the call to examine our hearts for false stakes. “What is my heart attached to?” we must frequently ask. “What am I allowing to form my character?”

Are our hearts anxious and angry? Do we find ourselves scapegoating our enemies? Do we harbor bitterness and resentment toward those who are different than us? Do we find ourselves prone to legalism? Do we judge others by our legalistic standards? Do we find ourselves overcome with greed?

Because our spiritual journey is not a zero-sum game, the reality is that each one of us will find our hearts bound in destructive ways. While it is anything but easy, the call to holiness is the call to sober self-reflection. Are there things to which I’m bound that are not of Christ? Is my soul being formed by things that compete with the Christian community? The call of the holy life is the call to break that which is, or will be, destructive and instead bind ourselves to the God who will make us the fullest and most beautiful versions of ourselves: the sons and daughters of God.