Should religious teachings confront the mysteries of the soul and make them plain? Or drive the listeners deeper into their own, necessarily uncomprehending selves? Should preachers provide questions or answers? Who ultimately decides what it’s all about?

This last question, central to every faith and creed, gets a workout in “Horizon,” the latest entry in unclassifiable exegesis by performance artist Rinde Eckert. The commanding yet serene Mr. Eckert, who punctuates his works with ambitious musical compositions tailored to his operatic tenor, has shifted his attentions from Western literature’s greatest religious allegory (2001’s “Moby Dick” homage “And God Created Great Whales”) to the very nature of religious allegory. In his circuitous fantasia on the power of parables, based loosely on the life and writings of Reinhold Niebuhr, he speaks to our insatiable desire for narrative while simultaneously withholding any sort of cohesion from his own tale. The result resembles the overflowing pockets of a brilliant seminarian: inventive, inconclusive, occasionally transcendent, and filled with false starts as it inches toward a synthesis of the known and the unknowable.

“Horizon” is constructed as the feverish ruminations of Reinhart Poole (Mr. Eckert), an unorthodox theologian who has been ousted from his teaching job and who is mulling a return to the ministry. It is the night before his final lecture, and Reinhart’s mind is swimming with flashbacks, pertinent parables, ideas for a comic play of his own, and an aria of rage at those who deify the written Gospel, “smug misguided fools … who make of it a golden calf.” Here and throughout, Mr. Eckert’s arresting score references everything from roadhouse blues to German lieder to barbershop ditties.

Among Reinhart’s memories are the recitations of dogma that he and his older brother received from their minister father — David Barlow and Howard Swain play these and many other supporting roles — and Mr. Eckert skillfully conveys how such litanies have informed Reinhart’s skepticism as well as his core beliefs. His accounts of the prodigal son and other pertinent parables, often delivered in a hypnotic sprechstimme, also derive their power from the disappearance of Reinhart’s brother years earlier.

Mr. Eckert and director David Schweizer employ numerous narrative styles in telling a story about a man who himself tells stories as a way of tiptoeing toward the inexplicable. This hall-of-mirrors quality, however, curdles during the snippets of Reinhart’s unfinished play, a comedic — you guessed it — allegory about two rustic masons who have spent the last 17 centuries building and then dismantling the foundation of a church.

The play-within-a-play wears its literary antecedents (Samuel Beckett, Luigi Pirandello) on its sleeve, and Messrs. Barlow and Swain’s performances as the two masons frequently lapse into archness here. (Their music-hall vocal material is also among Mr. Eckert’s least inspired.) Mr. Schweizer and set designer Alexander Nichols do, however, make deft use of the cinder blocks that clutter the New York Theatre Workshop stage; the masons’ efforts yield an imposing, ever-changing structure that becomes a seat, a lectern, and a prison of sorts before Reinhart demolishes the wall with a force that would do the trumpeters of Jericho proud.

From original sin to martyrdom, “Horizon” finds room for numerous aspects of Christianity and its more troubling interpretations. Fittingly for the story of a heretical theologian, the devil also gets more than his due. In fact, he gets something close to the last word: God’s voice goes unheard throughout the play, but the devil (brought to icy life by a grinning Mr. Barlow) recounts his fall from grace and his responsibility to “speak these truths God cannot speak” in a sort of deistic good-cop-bad-cop routine.

“This is the nature of truth,” he continues, “to be despised and indispensable.” Truth is clearly a slippery construct for Mr. Eckert, and the fact that he comes no closer to finding it by the end of “Horizon” is hardly cause for criticism. The very act of looking represents a small but necessary step toward grace.

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With Cormac McCarthy and Christopher Hitchens topping the best-seller lists, beach reading has taken on a distinctly erudite air this summer. So may I suggest capping off your post-apocalyptic sojourns and atheistic tirades with some of the books honored earlier this weekend by the Theatre Library Association. The TLA routinely draws my attention to worthwhile performing arts offerings, and this year featured an unusually high number of intriguing titles.

Three theater-themed books were picked this year, not counting Birgitta Steene’s “Ingmar Bergman: A Reference Guide,” which exhaustively chronicles the director’s stage as well as film history. (Bergman himself, at 88, reportedly dips into the book when his memory fails him.) Two of the books go the small-bore route: The late Marvin Rosenberg and his widow, Mary Rosenberg, subject Shakespeare to a vigorous analysis in “The Masks of Anthony and Cleopatra,” while Bruce McClung’s “Lady in the Dark: Biography of a Musical” focuses on the pioneering 1941 musical by Kurt Weill, Ira Gershwin, and Moss Hart. (A brief snippet of the show can currently be heard in the Weill musical “LoveMusik.”) And another German composer is examined through a broader lens in “Wagner and the Art of the Theatre,” by Patrick Carnegy. Plenty to keep theatre fans busy through the fall, in other words, even without the 1,150 pages on Bergman.

Until July 1 (79 E. 4th St., between Second Avenue and the Bowery, 212-239-6200).