Christ's mercy encompasses all men. He desires the salvation of everyone, and so we approach Him with confidence that He will have mercy on the Holy Souls in Purgatory, who have already proved their love for Him.
Prayer for the Holy Souls in Purgatory
O Lord, who art ever merciful and bounteous with Thy gifts, look down upon the suffering souls in purgatory. Remember not their offenses and negligences, but be mindful of Thy loving mercy, which is from all eternity. Cleanse them of their sins and fulfill their ardent desires that they may be made worthy to behold Thee face to face in Thy glory. May they soon be united with Thee and hear those blessed words which will call them to their heavenly home: "Come, blessed of My Father, take possession of the kingdom prepared for you from the foundation of the world."