Go Tell It on the Mountain delves into John Grimes' quest to uncover his authentic self, distinguishing his personal values from those of the people around him. The story's timing on his birthday is intentional, symbolizing his step into maturity, specifically his fourteenth birthday, which marks the shift from childhood to adolescence and the beginning of puberty. Growing up is fundamentally about discovering one's identity.

John is part of a family that is deeply involved in his life. However, his father's insensitivity and bullying nature make it difficult for him to accept that his family's identity defines him. Even without the knowledge that Gabriel Grimes is not his biological father, John keeps him at a distance. This separation can be attributed to Gabriel's harsh demeanor, whereas Roy's rebellious nature reflects Gabriel's own childhood, possibly influenced by his father's indulgent behavior.

John imagines himself as the "Great Leader of his People," a fantasy clearly shaped by his Biblical education. He clings to this hope, seeing glimpses of its possibility in the praise he receives at school. However, his family's deeply rooted values lead him to view himself as a sinner. When John looks in the mirror, he remains uncertain, "for the principle of their unity was indiscernible, and he could not tell what he most persistently desired to know: whether his face was ugly or not."

To address his identity crisis, John broadens his interests beyond his family's influence and forms a connection with an outsider, Elisha. The intense religious experience he undergoes at the end fulfills his identity quest in multiple ways: it allows him to emulate Elisha by having a similar seizure; it satisfies the devout side of his family by "converting" him into their religious life; and it gratifies his youthful ego by being loud and attention-grabbing.