The Mercy of our God is, and always has been a grand part of our faith. Word of His mercy spreads throughout Scripture, including in the Gospels "Blessed are the merciful, for they shall obtain mercy." Christ's Divine Mercy did not start with St. Faustina, but it is His very being. His Mercy has always been present to us. This new revelation is a continuation of that presentation of His Heart which is full of love and mercy for all. In 1935, this prayer for mercy all started with a Polish sister who heard the Lord's deep cry to pour His mercy out upon His children. St. Faustina Kowalska was a faithful sister who was called by God to spread a message in an extraordinary way. It all began with visions of Jesus during St. Faustina's prayer time, Christ asked her to have an image commissioned (similar to the one in the portrait of the Saint here) and for it to be venerated at the sisters' chapel in Poland, then shown to the whole world.
In order to spread this word of mercy, she first of all continued to pray. As time went on, she received visions from the Lord and was prompted to write the revelations down. St. Faustina has a whole diary published for us to read now and see how Christ revealed Himself to her during prayer.
"Say unceasingly the Chaplet that I have taught you. Whoever will recite it, they will receive great mercy at the hour of death. Priests will recommend it to sinners as their last hope of salvation. Even if there were a sinner most hardened, if he were to recite this chaplet only once, he would receive grace from My infinite mercy." (Diary, 687)
With the guidance of her spiritual directors, Faustina was obedient to God and the message of mercy spread throughout the world, and continued to spread when St. John Paul II declared the second Sunday of Easter to be consecrated to Divine Mercy. The hour of Mercy is 3:00pm each day, remembering the hour Christ died on the Cross. Many people pray the Divine Mercy Chaplet each day during that hour. As we continue to pray through Lent, let us continue to enter into Christ's Mercy by receiving it and showing others Mercy.
I demand from you deeds of mercy which are to arise out of love for me. You are to show mercy to your neighbors always and everywhere. You must not shrink from this or try to excuse yourself from it (Diary, 742).