ST. MARY FAUSTINA KOWALSKA was born on 25 August 1905 in Głogowiec, Poland, to a poor, religious family of peasants, the third of 10 children. She was baptized with the name Helena in the parish church of Swinice Warckie. From a very tender age she stood out because of her love of prayer, work, obedience and her sensitivity to the poor. At the age of nine she made her First Holy Communion and attended school for three years. At the age of 16 she left home and went to work as a housekeeper in Aleksandrów, Lódz and Ostrówek in order to support herself and to help her parents.

At the age of seven she had already felt the first stirrings of a religious vocation. After finishing school, she wanted to enter the convent but her parents would not give her permission. Called during a vision of the suffering Christ, on 1 August 1925 she entered the Congregation of the Sisters of Our Lady of Mercy and took the name Sister Mary Faustina. She lived in the congregation for 13 years, residing in Kraków, Płock and Vilnius, where she worked as a cook, gardener and porter.

Externally, nothing revealed her rich mystical interior life. She zealously performed her tasks and faithfully observed the rule of religious life. She was recollected, yet very natural, serene and full of kindness and disinterested love for her neighbor. Although her life was apparently insignificant and monotonous, she hid within herself an extraordinary union with God.

It is the mystery of God's mercy, which she contemplated in the word of God as well as in her everyday activities, that forms the basis of her spirituality. The process of contemplating and getting to know the mystery of God's mercy helped to develop within Sister Mary Faustina the attitude of childlike trust in God and of mercy towards her neighbor. "O my Jesus, each of your saints reflects one of your virtues; I desire to reflect your compassionate heart, full of mercy; I want to glorify it. Let your mercy, O Jesus, be impressed upon my heart and soul like a seal, and this will be my badge in this and the future life" (Diary 1242). Sister Faustina was a faithful daughter of the Church. Conscious of her role in the Church, she cooperated with God's mercy in the task of saving lost souls. At the specific request of the Lord Jesus and following his example, she made a sacrifice of her own life for this very goal. Her spiritual life was also distinguished by a love of the Eucharist and a deep devotion to the Mother of Mercy.

The years she spent in the convent were filled with extraordinary gifts, such as revelations, visions, hidden stigmata, participation in the Passion of the Lord, bilocation, the reading of human souls, prophecy and the rare gift of mystical espousal and marriage. Her living relationship with God, the Blessed Mother, the angels, the saints, the souls in purgatory — with the entire supernatural world — was as real for her as the world she perceived with the senses. In spite of being so richly endowed with extraordinary graces, Sister Mary Faustina knew that they do not in fact constitute sanctity. In her Diary she wrote: "Neither graces, nor revelations, nor raptures, nor gifts granted to a soul make it perfect, but rather the intimate union of the soul with God. These gifts are merely ornaments of the soul, but constitute neither its essence nor its perfection. My sanctity and perfection consist in the close union of my will with the will of God" (Diary 1107).

The Lord Jesus chose Sister Mary Faustina as the apostle and "secretary" of his mercy, so that she could tell the world about his great message. "In the Old Covenant", he said to her, "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).

The mission of Sister Mary Faustina consists in three tasks: — reminding the world of the truth of our faith revealed in the Holy Scripture about the merciful love of God towards every human being;

 — entreating God's mercy for the whole world and particularly for sinners, among others through the practice of new forms of devotion to the Divine Mercy presented by the Lord Jesus, such as: the veneration of the image of the Divine Mercy with the inscription: "Jesus, I trust in you"; the feast of the Divine Mercy celebrated on the first Sunday after Easter; chaplet to the Divine Mercy and prayer at the Hour of Mercy (3 p.m.). The Lord Jesus attached great promises to the above forms of devotion, provided one entrusted one's life to God and practiced active love of neighbor;

 — initiating the apostolic movement of the Divine Mercy, whose task is to proclaim and entreat God's mercy for the world and to strive for Christian perfection, following the precepts laid down by Sister Mary Faustina. The precepts in question require the faithful to have an attitude of childlike trust in God, expressed in fulfilling his will, and an attitude of mercy toward one's neighbor. Today millions of people throughout the world are involved in this Church movement: it includes religious congregations, lay institutes, religious, confraternities, associations, various communities of apostles of the Divine Mercy, as well as individuals who take up the tasks which the Lord Jesus communicated to them through Sister Mary Faustina.

Sister Mary Faustina's mission was recorded in her Diary, which she kept at the specific request of the Lord Jesus and her confessors. In it she faithfully wrote down all of the Lord's wishes and described the encounters between her soul and him. "Secretary of my most profound mystery", the Lord said to Sister Faustina, "know that your task is to write down everything that I make known to you about my mercy, for the benefit of those who by reading these things will be comforted in their souls and will have the courage to approach me" (Diary 1693). Sister Mary Faustina's work sheds light on the mystery of the Divine Mercy. It delights not only simple, uneducated people, but also scholars, who look upon it as an additional source of theological research.

Sister Mary Faustina, consumed by tuberculosis and innumerable sufferings, which she accepted as a voluntary sacrifice for sinners, died in Kraków at the age of 33 on October 5, 1938, with a reputation for spiritual maturity and a mystical union with God. Her reputation for holiness grew, as did the devotion to the Divine Mercy and the graces received from God through her intercession. Pope John Paul II beatified Sister Faustina on 18 April 1993. She was canonized a saint on April 30, 2000. Her mortal remains rest at the Shrine of the Divine Mercy in Kraków-łagiewniki. Her feast day is on October 5.