Thérèse of Lisieux was a joyful and carefree child—until her mother died when she was just four years old. She became timid and easily agitated. But many years later on Christmas Eve, all of that changed. After celebrating the birth of Jesus with her church community, she experienced God releasing her from her fear and giving her joy. She attributed the change to the power of God leaving heaven and becoming a man, Jesus, and through His dwelling in her.

What does it mean for Christ to dwell within us? It’s a mystery, said Paul to the Colossian church. It’s one…