In the Diary of St. Faustina, she recorded a number of promises which Jesus made to those devoted to His Divine Mercy. We selected a few of the most powerful of these promises for this article, with a special focus on praying the Chaplet of Divine Mercy. It is worth reading these promises a number of times to fully understand them.
"Oh, what great graces I will grant to souls who say this Chaplet. Write down these words, my daughter. Speak to the world about My mercy; let all mankind recognize my unfathomable mercy. It is a sign for the end times; after it will come the day of justice. While there is still time, let them have recourse to the fount of my mercy; let them profit from the blood and water which gushed forth for them" (Diary, 848) .
"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).
"At the hour of their death, I defend every soul that will say this Chaplet as I do my own glory. When this Chaplet is said by the bedside of a dying person, God's anger is placated and His unfathomable mercy envelops the soul" (Diary, 811)
"I desire that this mercy flow out upon the whole world through your heart. Let no one who approaches you go away without that trust in my mercy, which I so ardently desire for souls. Pray as much as you can for the dying. By your entreaties, obtain for them trust in my mercy, because they have most need of trust, and have it the least" (Diary, 1777)
"My daughter, help me to save a certain dying sinner. Say the Chaplet that I have taught you for him. When I began to say the Chaplet, I saw the man dying in the midst of terrible torment and struggle. His Guardian Angel was defending him, but he was, as it were, powerless against the enormity of the soul’s misery. But while I was saying the Chaplet, I saw Jesus just as He is depicted in the Image. The rays that issued from Jesus’ heart enveloped the sick man, and the powers of darkness fled in panic. The sick man peacefully breathed his last" (diary, 1565)