The Greek word eros (the root of “erotic”), didn’t originally mean something sexual. Our closest translation of eros is “passion.” In the broadest sense, passion means the invigorating energy that fuels our pursuits, desires, and ambitions. Of course passion can be sexual, but sexuality is only one of many avenues. We can be passionate about our families, about our work, about our hobbies, about causes such as racial reconciliation or ecology—we can even passionate about grammar or the Dewey decimal system.

To help their students understand the full importance of passion, philosophers often compared eros to fire. Like fire, passion can focus us, it can draw us together, it can provide protection and safety. There are also dangers. Passion can consume us, escaping its intended confines and running roughshod over the rest of our lives.

I’ve spent 118 hours writing a Teaching Atlas on City Theology. The Teaching Atlas project is a Westwinds initiative I began nearly seven years ago because I am passionate about providing theological, biblical, and relational resources for Christians.

During my writing week, I had several bouts of listlessness, times when I was forced to realize my passion had diminished. Whether from exhaustion or boredom or simply because I had run out of things to say (or interesting ways to say them), I realized the fire inside had gone out. Please understand, when you’ve only got a week to write a 50,000-60,000 word manuscript, you cannot afford the luxury of waiting for your passion to reignite itself; no, you’ve got to do everything you can in order to get that flame white-hot as fast as possible.

I returned to the metaphor of fire for inspiration.

Every fire needs two kinds of fuel: kindling and firewood. You use kindling (and maybe some paper or lighter fluid) to get the fire started. Kindling burns easily, but is also consumed quickly. Our passions also have kindling—ideas, insights, role models, or materials that cause our imaginations to flare up and kick us into high gear. Firewood is the fuel that keeps the fire burning longest and hottest. You can’t use firewood to start the fire, but you can’t sustain it with kindling. The firewood of our passion is usually the hard stuff—the intense research, the discipline and practice, the late hours, etc.—that requires much effort for a more sustainable yield.

When I was writing The Garden-City Epistles and felt my passion flag, I turned first to the kindling—the City Psalms (Psalm 46, for example), Revelation 21, or the writing of Tim Keller—but, eventually, the kindling did little to stoke my fire. I was then forced to use the big wood—Jacques Ellul, Harvie Conn, GK Beale—which made things slower, but also added a layer of necessary credibility to my writing that, otherwise, would not have been present.

Both kinds of fuel were needed in order to sustain my passion.

What’s your passion? What got you interested in it in the first place? What triggered your enthusiasm? Have you gone back to that kindling for renewed passion?

If you have, you probably know there are only so many times you can remember your conversion, or fall in love with that cute smile, or experience the joy of jumping around just for fun. There comes a time when the first spark ceases to spark. We become bored.

I think this happens to many Christian kids who grow up in Christian homes. They’ve heard it all and seen it all and feel like they know it all, even if they’re self-aware enough to realize they do not. Unless they do the hard work of chasing down unexplored avenues of faith, learning new ways to read scripture and pray, they will spend their lives as bored, listless, cultural Christians with no resemblance to the heroes in the Second Testament.

And so will you.

We’re the ones responsible for keeping our fire burning hot. We can’t just hope it happens on its own. We have to feed the fire within us. We have to use the fast-burning, super-exciting stuff to get our fires hot enough to burn the stuff that lasts.