The Divine Mercy is a devotion to the merciful love of God and the desire to let that love and mercy flow through one's own heart towards those in need of it.[3] The devotion is due to the apparitions of Jesus received by Saint Mary Faustina Kowalska (1905-1938), who is known as the Apostle of Mercy.

Faustina Kowalska reported a number of apparitions, visions and conversations with Jesus which she wrote in her diary, later published as the book Diary: Divine Mercy in My Soul.

The three main themes of the devotion are to ask for and obtain the mercy of God, to trust in Christ's abundant mercy, and finally to show mercy to others and act as a conduit for God's mercy towards them.

The devotion places emphasis on the veneration of the Divine Mercy image which Faustina reported as a vision of Jesus while she was in her cell in the convent.[5] The image is displayed and venerated by Catholics on its own, and is solemnly blessed during Divine Mercy Sunday. 

The devotion includes specific prayers such as the Chaplet of Divine Mercy.

The Divine Mercy devotion is followed by over 100 million Catholics, and is also recognised and celebrated in the Anglican Communion.

The primary focus of the Divine Mercy devotion is the merciful love of God and the desire to let that love and mercy flow through one's own heart towards those in need of it.[3] As he dedicated the Shrine of Divine Mercy, Pope John Paul II referred to this when he said: "Apart from the mercy of God there is no other source of hope for mankind".