Go Tell It on the Mountain, James Baldwin's seminal semi-autobiographical novel, deals primarily with the conversion experience of John Grimes, a 14-year-old African-American teenager living in 1930s Harlem with his family. Though the novel takes place in the space of a weekend, Baldwin also reveals the life stories of John's stepfather, Gabriel, John's mother, Elizabeth, and John's aunt, Florence (sister of Gabriel).
After a wild and profligate childhood, Gabriel experiences conversion and becomes a preacher. Assured of his place as one doing the work of the Lord, he is nevertheless an abusive father and husband embittered by the seeming failure of God to provide a son who would continue his work. His marriage to his first wife Deborah had failed to produce a son; before her death from natural causes, he has an affair with a woman named Esther, who goes North after getting pregnant and being spurned by Gabriel. The son she bears is like Gabriel: wild and uncontrolled, he died at the hands of white men he had angered. After Deborah dies, Gabriel marries Elizabeth, who bore John from a former affair. She also bears him a son, Roy, who proves to be as wild as Gabriel was. Though John is obviously the son he has been promised, he despises John and thinks of him as the devil's child, the result of sin.
Elizabeth led a sheltered life as a child until she met Richard, the non-church-going, sullen clerk who ends up falling in love with her. They essentially run away together. Shortly after becoming pregnant, Richard commits suicide; so, Elizabeth has to fend for herself. She becomes friends with Florence, who introduces her to Gabriel. Drawn to the protection Gabriel (who thinks he is raising up Elizabeth and her son) offers, she marries him and becomes a long-suffering, patient woman.
Florence, Gabriel’s sister, has resented Gabriel since his birth for taking away the opportunities for education and ambition she so strongly desired. After running away from her mother and brother, she marries Frank, who turns out to be a disappointment. After their marriage fails, Florence is left to fend for herself, which she does with fierce pride and dignity. Having scorned the church ever since Gabriel's alleged conversion, she keeps a close eye on the women he marries and stands up to Gabriel for them. By the time of the events of the book, she is hard and embittered by her life and angry from the incurable disease forcing her to come face-to-face with God before she dies.
The book closes with John rising from the threshing-floor, the place where he had come face-to-face with his need for salvation and accepted it. John is clearly the fulfillment of Gabriel's desire for a son on fire for the Gospel, perhaps surpassing even Gabriel in his joy and excitement over his salvation. Nevertheless, Gabriel remains deeply skeptical.