I saw my Guardian Angel, who ordered me to follow him. In a moment I was in a misty place full of fire in which there was a great crowd of suffering souls. They were praying fervently, but to no avail, for themselves; only we can come to their aid. The flames which were burning them did not touch me at all. My Guardian Angel did not leave me for an instant. I asked these souls what their greatest suffering was. They answered me in one voice that their greatest torment was longing for God.
-St. Faustina Kowalska
Prayer for the Holy Souls in Purgatory
Lord Jesus, have mercy on the souls detained in Purgatory. It was for their salvation that you took on our human nature and suffered a most painful death. Have mercy on their burning desire to see you, have mercy on their tears of repentance. Through the merits of your Passion, remit the sentence they incurred by their sins.
Dear loving Jesus, may your Blood descend on those dear souls! May it shorten their time of atonement and may they soon be called to eternal happiness in your Presence!