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 that God “kept hidden for ages and generations” (Colossians 1:26), but which He disclosed to the Lord’s people. To them God revealed “the glorious riches of this mystery, which is Christ in you, the hope of glory” (v. 27). Because Christ now dwelled in the Colossians, they experienced the joy of new life. No longer were they enslaved to the old self of sin.

If we’ve asked Jesus to be our Savior, we too live out this mystery of His dwelling in us. Through His Spirit, He can release us from fear, as He did Thérèse, and grow within us the fruit of His Spirit, such as joy, peace, and self-control (Galatians 5:22–23).

As we celebrate His birth, let’s give thanks for the wonderful mystery of Christ within us.