At the heart of The Potting Shed lies the profound theme of rebirth. The potting shed itself serves as the symbolic backdrop for James's miraculous revival. Enveloped by bulbs and seed packets, the shed is a sanctuary of burgeoning life. Paradoxically, it was within this very place that James, burdened by the suffocating, godless humanism instilled by his father, attempted to take his own life. Yet, much like Lazarus, he emerged anew, embracing a committed Christian faith. This transformation underscores the powerful interplay between despair and redemption, life and death, set against the timeless cycle of renewal and growth inherent in nature itself.

At the heart of Graham Greene's play lies a poignant exploration of the erosion of childhood innocence, a theme that finds powerful expression through the character of Old Mr. Callifer. His relentless mission to dismantle belief in the supernatural leaves a profound impact on the young James, stripping away his innocent faith and pushing him to the brink of despair and ultimately, a tragic attempt at suicide. Callifer's intellectual pursuits, encapsulated in his works like The Cosmic Fallacy and He Was a Man, stand in stark opposition to the nurturing and life-affirming environment represented by the potting shed.

The books, with their cold logic and denial of divinity—arguing that Jesus was nothing more than a Palestinian religious figure—serve as a symbol of intellectual arrogance. In contrast, the potting shed, filled with seeds and bulbs, becomes a metaphor for renewal and growth. It is here that Mrs. Potter's simple faith in the natural cycle of life and spirit triumphs over Callifer's attempts to impose sterile rationalism on the world. Thus, Greene weaves a narrative where the instinctive and innate belief in spiritual and natural rebirth stands resilient against the corrosive influence of cynical adulthood.

The notion of a priest proposing to sacrifice his faith to save his nephew’s life initially appears contrived, almost like a calculated challenge to divine intervention rather than an earnest prayer from a man driven by profound love. This act, seemingly theatrical, raises questions about its authenticity and the depth of desperation that would prompt such a gesture. It’s not merely the dramatic gesture that captures attention; it’s the delayed impact of the miracle that intrigues. The nephew, James, only experiences true spiritual renewal decades later, when his uncle finally reveals the events that transpired in the potting shed. This revelation illustrates the complex interplay of faith, sacrifice, and the passage of time in understanding and appreciating the profound nature of such a miracle.

The events that transpire in the shed profoundly affect James's family, though he remains oblivious to this shift. His father's strict rationalism, which overshadowed James’s childhood, now faces a challenge in the wake of James's rebirth. This personal resurrection not only shatters the family's long-held belief that life is devoid of supernatural elements, but it also dismantles his father's lifelong endeavor to eradicate faith in God. In a twist of fate, James's transformative experience casts doubt on the foundations of his father's rationalist philosophy, echoing through the family and unsettling their once steadfast convictions.