Prayer for a loved one's conversion

St. John's Manual, 1856

O God, have mercy on me a sinner, and permit me to offer Thee my earnest supplications on behalf of all souls in sin; for Thou willest not the death of a sinner, but his conversion. When Moses besought Thee to pardon a rebellious nation, Thou couldst not resist his entreaties. It grieves Thee, when none interpose to appease Thine anger; Thou commandest us to pray for one another, assuring us that; by causing a sinner to be converted from the error of his ways, we deliver our own souls from death, and cover a multitude of iniquities. Relying on thy merciful promises, I come before Thee with great confidence, to implore for others the pity I so much need myself. Forgive them, O Lord! for they know not what they do; open their eyes, that entering into themselves, they may see the extent of their crimes, and feel how sad a misfortune it is to have forsaken Thee. 

Open their ears to the sound of that Almighty voice, which can raise the dead to life; soften the obduracy of their hearts, that they may no longer resist Thy grace. Remember Thy tender mercies; remember the precious blood of Jesus Christ; save the souls which have been purchased at so great a price. Hear our prayers, inspired by the Spirit of thine own charity, and offered from the sole motive of pleasing and glorifying Thee. Amen.