Most of the art and literature of friendship is elegiac. From Montaigne to Marsden Hartley, from St. Aelred to Andrew Sullivan, from elegant tribute to anguished lament, our art of friendship is haunted by the death of friends.

There are many reasons for this. Friendships are typically less public than marriages or parental relationships; for most of our lives they play in gentle counterpoint against these more public relationships, only emerging in moments of anguish. Friendships don’t produce children, so art can serve as a memorial—something to last when the friend is gone, something to prove that the friendship had weight in the world.

And friendships, especially in the modern and postmodern eras, are free of promises to stick by one another. We only know a friendship is lifelong in retrospect. Often we only see the depth of a friendship, its endurance and the way it shaped a life, when death has parted the friends.

Part of what makes my friend Wesley Hill’s slender new book so intriguing is that it is an attempt to give an account of friendship that is grounded in history, theology, and literature—yet forward-looking. Spiritual Friendship: Finding Love in the Church as a Gay Christian is an essayistic collection of provocations, not a tome intended to be “the last word” on friendship or its relationship to Christian community. It’s a book about hope and hope’s uncertainty, about trust and taking chances; it’s not a look back at a friendship well-lived. It’s an unfinished story.

The book is divided into two sections. Both sections seamlessly weave Hill’s personal experience, passages from literature and descriptions of artwork, historical and sociological interpretations, and theological reflection. The first section is weighted more heavily toward the theoretical: Hill asks how friendship lost its public character, and why men, especially, find the intimacy and vulnerability of deep friendship much harder to attain after middle school. But even in this section he shows how the longing for friendship has shaped his own life, and how difficult it has been to acknowledge and understand that longing.

Hill asks whether and how friendship should shape Christian lives. He engages with the Christian arguments against friendship—shouldn’t Christians love everybody, not just the people we especially like?—and suggests that for Christians the terms “friend,” “brother/sister,” and “disciple” should intertwine. I think there’s a lot more to say here: What about friendships with non-Christians? Will mixing friendship (a relationship we basically choose, and one which is based on at least initial affection and attraction, pleasure in the other person’s presence) and discipleship (a relationship with those whom we often would not choose, who are different and to whom we are tied through our common love of Jesus rather than directly to one another) make it easy to turn away from the hardest parts of discipleship, to retreat into a circle of friends? I specifically wonder how the vision of a church “molecule” made up of the atomic bonds between friends would become a cross-class church. Wouldn’t class segregation be easier in a church based so heavily on chosen bonds, whether friendship or other forms of kinship?

The great thing about Hill’s book, though, is that it prompts these questions (and many others) and doesn’t attempt to resolve them. It has already prompted one terrific reflection on how friendship might fit into a class-crossing church.

The second half of the book draws us deeper into Hill’s own story, which we’ve glimpsed in the earlier sections. He describes one friendship that basically shattered under the weight of his own expectations and unacknowledged needs. He stumbles around for a while in the rubble of that friendship, meeting other people and trying again—with that heartbreaking caution which is the result of pain and failure—to open his heart to others and intertwine his life with theirs.

And the book closes with an extended description of his friendship with a married couple. This friendship has affected their decisions around work and housing; the friendship has been blessed by a minister, and after the blessing the friends received Communion together, in a renewal of one of the most beautiful friendship practices of premodern Christendom.

But, in the words of Schmendrick the Magician, “There are no happy endings–because nothing ends.” Throughout this touching scene Hill has been reminding us that the future of this friendship is uncertain: “I know we’ll see further complications in our friendship down the road. … And I know that, modern life being what it is and with none of us being quite ready to take a vow of stability, we’ll likely find ourselves saying a more permanent good-bye at some point in the future, perhaps even as soon as next year.” He focuses on gratitude for the time they have had together, and tries to hold love lightly.

The old saying goes, “Man plans; God laughs.” Or in the AA formulation, “Expectations are premeditated resentments.” In a way, the second half of Hill’s book is a meditation on the difference between plans and promises.

Plans are fantasies which take place in an alternate universe where we control the most important aspects of our lives. Promises, by contrast, often explicitly highlight the uncertainty of the future: I will be your friend come what may. The wedding vows are a litany of all the hardship that may lie in wait for the couple: for richer or for poorer (layoffs, financial crashes which turn your smart decisions suddenly foolish, the tears leaking from her eyes as she stares at that second line on the pregnancy test), in sickness and in health (disability, depression, the emotional and financial struggles which illness brings), for better or for worse (this isn’t who I thought I married; I don’t know if I can do this). And then the final blow, once you’ve somehow learned to live with all the rest: ’til death do you part.

God may laugh at our plans, but I don’t think He laughs at our promises. Where other books on friendship gain their depth and poignancy from their attention to a friendship which has ended, which perhaps we weren’t grateful enough for when we had it, Hill’s book gains its richness from his attention to and gratitude for a friendship which is only beginning. That’s appropriate for a book which is about the future of friendship itself.

Eve Tushnet is a TAC contributing editor, blogs at Patheos.com, and is the author of the recently-released book Gay and Catholic: Accepting My Sexuality, Finding Community, Living My Faith.