God appears to 11-year-old Tracy Richards, a precocious girl dealing with her parents' impending divorce. He chooses Tracy because her strong belief in goodness makes her the perfect candidate to help Him spread His message. God tasks Tracy with developing a slogan that encourages people to believe in Him, aiming to rekindle faith and positivity in a skeptical world. Tracy enthusiastically embraces the challenge and begins brainstorming ideas to promote a fresh sense of belief and hope among those around her. As she works on the assignment, she faces typical challenges of childhood, including school and friends, but her focus remains on the important task God has given her.

Tracy enlists the help of her best friend, Shingo, in distributing flyers and posters with their slogan. As they carry out their mission, they must confront various adults who dismiss their efforts as childish or nonsensical. Tracy's belief is unwavering, and she manages to inspire those around her to reconsider their understanding of faith and belief in miraculous possibilities. Despite skepticism from many quarters, Tracy’s commitment and earnestness slowly begin to have an impact. Meanwhile, her parents remain largely unaware of the divine mission unfolding in their daughter's life, preoccupied with their own issues. Tracy’s journey becomes not only a quest to fulfill God’s request but also a path of self-discovery and reconciliation within her family.