Jerry Landers, portrayed by John Denver, is an assistant manager at a grocery store in Burbank, California, living a seemingly ordinary life with his wife, Bobbie, played by Teri Garr. One day, he receives a perplexing letter summoning him to a meeting with God the very next day. Initially, Jerry and Bobbie deem it a mere prank, leading him to tear the note into pieces and dispose of it. However, fate takes a curious turn when the next day, the letter mysteriously reappears in a head of lettuce at the store, prompting Jerry to reconsider its significance and fulfill the unusual request.
In an unsettling twist, when Jerry arrives at the designated meeting place in downtown Los Angeles, he encounters an empty office furnished only with a chair and an intercom. It is here that he hears a voice introducing itself as God, who attempts to persuade Jerry of His authenticity by showcasing an uncanny reality: Jerry is located on the 27th floor of a building that, in reality, has only 17 floors. After this alarming revelation spooks him enough to leave the building in confusion, God channels his voice through Jerry's "broken" car radio to further convey His message. The divine being urges Jerry to enlighten others of His existence and spread goodness across the world.
Returning home, Jerry shares his bewildering encounter with Bobbie, but she remains skeptical and suggests a vacation to visit his brother-in-law, a therapist. He adamantly defends his sanity, igniting Bobbie's concerns about his mental state. The following day, Jerry experiences yet another divine interaction—in the shower, God presents Himself as an elderly man played by the illustrious George Burns. When Jerry questions God about the injustice and suffering in the world, He explains that life is governed by luck and free will, thereby emphasizing Jerry’s role in promoting kindness and preservation of the Earth to mankind.
With a newfound sense of purpose, Jerry endeavors to share God's message with the press. He approaches Briggs, a journalist portrayed by George Furth, but faces immediate skepticism. Later, during a grocery store visit, God instructs Jerry to take a drive, and in a humorous twist, causes rain to pour inside the car as a sign. When Jerry is stopped by a police officer and fabricates a lie about a car wash to explain the water, God expresses disappointment in Jerry's dishonesty and encourages him to spread His word with integrity.
Despite Jerry's efforts to convince Briggs and the subsequent media attention that sweeps through his life, the placating tone of his revelations about God is met with embarrassment from his wife and confusion from their children, Adam and Becky. As the media frenzy escalates outside their home, a Food World executive, alarmed by Jerry's claims, warns him to cease speaking of his encounter with God if he wishes to keep his job. In a pivotal moment, God reminds Jerry that although there are no guarantees in life, the sacrifices he makes now are essential to save the world.
During a segment on the Dinah Shore Show, Jerry's proclamation garners both attention and controversy, inciting mobs of religious fervor outside his residence. When religious leaders convene a committee to interrogate Jerry about his divine claims, his faith is put to the ultimate test, leading him to a tense standoff with the committee in a hotel. With God's assistance disguised as room service, Jerry diligently answers complex questions posed in ancient Aramaic.
At a revival meeting led by Paul Sorvino, tension mounts as Jerry reveals God's words, resulting in chaos and an unexpected ejection from the venue. Matters come to a head when Reverend Williams sues Jerry for slander, leading to a courtroom showdown where Jerry decides to represent himself, calling upon God to the witness stand. To the astonishment of all present, God appears and demonstrates His divine power through a card trick, yet when the testimony is recorded, it inexplicably vanishes from documentation, compelling the judge to dismiss the case due to lack of evidence.
Despite this bizarre turn of events, reconciliation blooms between Jerry and Bobbie, as she begins to believe in his encounters. As the narrative closes, Jerry faces the unanticipated consequence of losing his job, gathering his final paycheck, and bidding farewell to coworkers who no longer comprehend his mission. While driving away, he encounters a ringing payphone in a park, leading him to stop and answer. In another whimsical encounter, God materializes beside him to reassure Jerry that their efforts were not in vain despite the personal sacrifices made. With prophetic wisdom, God encourages Jerry to witness the unfolding of their endeavors, before bidding him farewell and fading into the ether, leaving Jerry with a mix of hope and uncertainty about what lies ahead.
