Gregory Cowles gestures at that question in his recent review of Mary Karr’s new book, The Art of Memoir. He notes the following in a parenthetical aside:

Given the inherently confessional nature of memoir, it may be no coincidence that so many of its most successful practitioners have been Catholic to some degree – Karr, Wolff, Harrison, and of course Augustine, but also Mary McCarthy, David Carr, Mary Gordon, Patricia Hampl, Frank McCourt – or that even non-Catholic memoirists slip so easily into the churchly narrative of penitence and redemption.

That prompted Paul Elie, who expresses some ambivalence about the matter, to admit Cowles might be on to something:

Cowles was the editor of my TBR cover essay on faith and fiction, and with this piece he furnishes part of the answer to the essay’s question of why Christian belief doesn’t figure into contemporary American fiction as much as we might expect.

It’s that it figures into memoir instead. I suggested as much at the end of the essay.

And why is that? Not, I think, because Catholicism is markedly confessional, but because the question about religion in our time – the question as framed by Catholics, at any rate – is whether it is true or untrue, and because memoir, with its affirmation that “this really happened,” may be better suited to that question than the novel is.  

I’m not so sure. The truth or untruth of religion is a perennial question; and the author of a memoir asserts not just that "this really happened," but "this really happened to me." A memoir deals with the remembered past, and as such is irreducibly subjective. Which is one reason why memoirs are so popular these days among religious and secular audiences alike, and why, yes, Catholics have written many great ones, but so have evangelical Christians, drug addicts, aging writers, and countless others. Memoir is exactly the form you would expect to thrive in our postmodern age; appeals to "objective truth" are viewed with suspicion, but personal experience and "speaking your truth" are nearly sacrosanct. To repurpose Elie's langauge, "Christian belief" really is "confessional," and it is precisely for that reason that religious memoirs gets an unusually respectful hearing these days. Theology might leave us cold, but testimony does not.

Admittedly this explains why religious memoirs are popular today more than it uncovers any deeper connection memoirs might have to Catholicism, or Christianity more broadly. Which is the question Cowles was getting at, I think, and that Elie's concern for the contemporary scene obscures. The matter of religious memoir's resonance or popularity today is not the same as the question of the broader connection between religion and memoir.

Cowles picks up on one rather obvious way of considering that connection when he notes that the "churchly narrative of penitence and redemption" lends itself to memoir. It's corollary is true, too: many "secular" memoirs reflect that churchly narrative, after a fashion. Generally speaking, you don't write a memoir at the nadir of your addiction, or in the midst of a divorce, or while the chemotherapy is leaving you bedridden. Memoirs mostly are written by survivors: people who somehow have gone through a set of experiences, or simply lived long enough to recount "what it was like." This might not mean "redemption," exactly, but perhaps "resolution," or something close to it. So Cowles is right to believe it's "no coincidence" that so many Catholics have produced memorable memoirs – there is a certain affinity between the faith and the literary form.

But even this explanation – which makes sense, as far as it goes – seems incomplete. Let me add an observation of my own.

Christians believe that every human being is created in the image of God, a claim that can be understood in a number of ways. It might serve as the basis for human rights – the imagio dei as the foundation for appeals to "human dignity." Or maybe it privileges human rationality: our capacity for reasoning reflects our most God-like endowment. The same might be said about human creativity; after all, Christians believe in a deity who is our Creator. Others could assert that, since Christians believe in a three-in-one God, the image of God should be construed as "sociality" – we are inherently relational creatures, social and political animals.

Yet we also know that God's self-understanding and self-knowledge always exceed the understanding and knowledge we have of God. Even revelation is accomodated to our all-too-human condition, our all-too-fallible capacities. We cannot know God the way God knows himself. There is an irreducible mystery to God's essence. To be creatures bearing God's image might mean, at least in part, that we are mysteries to each other. 

I wonder if this might suggest one reason why memoir could be thought of as "religious" or "Christian." Like the God who created us in his image, and whose ways are not our ways, we are not completely transparent to each other. The task of loving each other, which we are commanded to do, means loving those we cannot fully understand. Mere proximity doesn't dispel this mystery: who eludes us more than parents or siblings, friends or lovers?

Even more, we often don't understand ourselves, especially our younger selves. In one of my favorite memoirs, Christopher and His Kind, Christopher Isherwood refers to himself not as "me" or "I" but in the third-person as "Christopher" – indicating the distance he'd accrued from the youthful novelist who bounced around Berlin. And more than distance: a certain incomprehension, too. (Interestingly, that memoir ends with a nod to his eventual religious conversion – he came to be a serious student of Vedanta – which would be taken up in his last major work, another memoir titled My Guru and His Disciple.) 

And so we reach out to each other, stumbling along, telling our stories. We long to be known and loved, to be understood and embraced. There are different words to describe this, but the Christian word for it is grace.

I wonder, when we talk about the religious element to memoirs, and the form's enduring appeal, how much we are talking about that: the hope that our lives, failures and all, are not beyond the reach of mercy.