The Church has given no decision regarding the word "fire" in relation to Purgatory; but according to Theologians and Doctors of the Church. we are to understand a material fire. Concerning this, Bishop Colmar of Mayence, a great friend of the holy souls, writes: "Besides being deprived of the vision of God, the souls in Purgatory must also endure the tortures of a fire, the effects of which are so much more painful because it is an instrument in the avenging hand of God": a fire, as St. Augustine says, in comparison to which our material fire is as nothing; a fire that entirely penetrates the soul, in whatever manner this may be accomplished.
How, and to what extent this is done, we know not, but may draw our conclusion from similar instances. St. Gregory the Great says: "As the fallen angels, although pure spirits, are tormented by the material fire of Hell, so may a similar fire torture the souls of the departed in Purgatory." The justice of God can punish a spirit by means of a material substance as well as He can in His omnipotence give life to a body by the means of a spirit.
According to the holy Fathers, the fire of Purgatory does not differ from the fire of hell, excepting in point of duration. "It is the same fire," says St. Thomas, "that torments the reprobate in Hell, and the just in Purgatory, the least pain in Purgatory," he adds, "surpasses the greatest sufferings of this life." Nothing but eternal duration makes the fire of Hell more terrible than that of Purgatory.
Prayer: Refresh, O Lord, the suffering souls in Purgatory with the dew of Thy grace, that their pains may be relieved, and, in Thy mercy, hasten the moment of their deliverance, that they may meet Thee in Heaven where no fire but that of Thy holy love shall consume them. Through Christ Our Lord. Amen.
Special Intercession: Pray for all the souls in Purgatory, particularly for those who are forgotten by their relatives.
Lord grant them eternal rest and let perpetual light shine upon them. May they rest in peace. Amen. (Three times.)
Practice: Endeavor to spread the devotion to the holy souls as much as possible.
Invocation: My Jesus, mercy!