Helena Kowalska was born in Glogowiec, Poland, in 1905. She came from a poor and religious family of peasants; she was the 3rd of 10 children. As a very young child, Helena became known for her obvious love of prayer, work, obedience, and compassion for the poor. By the age of 7, Helena became aware of her calling to the religious life. Delayed because her parents would not give their permission for Helena to enter a convent, it took a vision of the Suffering Christ on 1 August 1925 to give her the determination to proceed with that calling. A few weeks before her 20th birthday, she was received as a postulant by the Sisters of Our Lady of Mercy in Warsaw, Poland, and took the name Sister Mary Faustina. During her time at the convent, Sister Mary Faustina was blessed with many graces, including visions, revelations, wounds of the stigmata (hidden from all but her), sharing in the Passion of the Lord, bilocation, the ability to read of human souls, prophecy, and mystical engagement and marriage.
Sister Mary Faustina was chosen by Our Lord as the Apostle and "Secretary" of His Mercy. He said to her "In the Old Covenant, I sent prophets wielding thunderbolts to My people. Today I am sending you with My mercy to the people of the whole world. I do not want to punish aching mankind, but I desire to heal it, pressing it to My Merciful Heart." (Diary 1588) Sister Mary Faustina's mission had 3 tasks:
At the request of Our Lord Jesus Christ, Sister Mary Faustina's recorded the details of her mission in a Diary. Being practically illiterate, she managed to write almost 700 pages in her diary phonetically.
Sister Mary Faustina died on 5 October 1938 of tuberculosis at a convent in Krakow, Poland. She was buried in the convent chapel beneath the image of the Divine Mercy. She was beatified on April 18, 1993. On 30 April 2000, Pope John Paul II canonized Maria Faustina Kowalska, Virgin, of the Sisters of the Blessed Virgin Mary of Mercy. The day of both her beatification and canonization were the Second Sunday of Easter, the Feast of the Divine Mercy, Mercy Sunday.