"With what measure you mete, it shall be measured to you again." (Matth.vii.2.) It will readily be seen that this word of the Divine Savior are applicable to the assistance we should render to the souls departed.
The learned Cardinal Cajetan says: "Those who in this life forget the departed, will, hereafter, in my opinion, be deprived in Purgatory of all participation in good works and devout prayers, though ever so many be offered for them by others; for Divine Justice is wont in this manner to punish their cruelty and hardness of heart."
Hence, he who shows no mercy towards the suffering souls and remains cold and indifferent to their pains, will, even though his soul may have escaped eternal damnation, languish in the flames of Purgatory without relief and consolation and look in vain for friends and intercessors. The faithful who do not forget the suffering souls completely, but seldom think of them, will not be deprived of friends and intercessors entirely, but will derive very little help and comfort, and their complaints will be answered by the words of St. Paul: "He who soweth sparingly, shall also reap sparingly." (2Cor. ix. 6)
Prayer: O God, whose goodness and mercy are infinite, have pity on the souls of those, who on account of their wont of charity, are undeserving of Thy bounty, and accept our fervent prayers in reparation for their faults, that they may not suffer without consolation. Through Christ, Our Lord. Amen.
Special Intercession: Pray for the souls who suffer for their want of charity.
Lord grant them eternal rest and let perpetual light shine upon them. May they rest in peace. Amen. (Three times.)
Practice: Bear patiently the ingratitude of others, and offer it for the souls in Purgatory.
Invocation: My Jesus, mercy!