Dozens of Missionaries of Charity novices gathered around the tomb and sang “Happy Birthday.”

In his message, Pope Benedict said celebrating Mother Teresa’s birth centenary “will be for the church and the world an occasion of joyful gratitude to God for the inestimable gift that Mother Teresa was in her lifetime, and continues to be through the affectionate and tireless work of you, her spiritual children.”

The pope said Mother Teresa was a living example of St. John’s words: “Beloved, if God so loved us, we must also love one another. No one has ever seen God. Yet, if we love one another, God remains in us, and his love is brought to perfection.”

He asked the order’s sisters, brothers, priests and lay members to let God’s love continue to inspire them to give themselves “generously to Jesus, whom you see and serve the poor, the sick, the lonely, and the abandoned” and to draw constantly from Mother Teresa’s example and spirituality.

After the visit to the tomb, Sr. Prema read a message from the congregation, and the group processed to the motherhouse’s L-shaped courtyard. Sr. Prema and Sr. Nirmala Joshi, retired superior general of the order, released white pigeons and blue and white balloons amid cheers from those packing the balconies on the three floors surrounding the courtyard.

Similar events were planned worldwide, including at Washington’s Basilica of the National Shrine of the Immaculate Conception.

Archbishop Lucas Sirkar of Calcutta said anniversary celebrations being held throughout India had brought “a ray of hope and joy to thousands of poor, underprivileged, disadvantaged, and marginalized in India,” especially as the nation struggles with violence, injustice and natural disasters.

The events were receiving wide media coverage, which was helping make the Gospel message better understood in India, he said in an Aug. 26 interview with Fides, the news agency of the Congregation for the Evangelization of Peoples.

Contributing to this story was Anto Akkara in Calcutta.