In 1903 Margarita María took the habit. She entered the contemplative life, from which was born her desire to spread the gospel all over the Earth.

The instrument for achieving this was the mission. The Order of the Blessed Virgin Mary of Mercy was founded to redeem Christian prisoners; she wished to extend this redemption to all human beings.

Firstly, in 1926, permission was obtained for occasional missions. Later, in 1930, the total transformation of the convent into a Missionary Institute was achieved.