From One Peter Five
There is in Purgatory, as in Hell, a double pain – the pain of loss and the pain of sense. The pain of loss consists in being deprived for a time of the sight of God, who is the Supreme Good, the beatific end for which our souls are made, as our eyes are for the light. It is a moral thirst which torments the soul. The pain of sense, or sensible suffering, is the same as what we experience in our flesh. Its nature is not defined by faith, but it is the common opinion of the Doctors that it consists in fire and other species of suffering. The fire of Purgatory, say the Fathers, is that of Hell, of which the rich glutton speaks, Quia crucior in hac flamma, “I suffer,” he says, “cruelly in these flames.”
–From Chapter IX of Purgatory: Explained by the Lives and Legends of the Saints by Rev. Fr. F.X. Schouppe, S.J.
The greatest punishment of Purgatory is in the first level above the darkness. The demons can touch it there. There is heat and cold, darkness and confusion, all coming from the punishment of Hell.
–Revelations to St. Bridget
The lowest region is filled with a fierce fire, but which is not dark like that of Hell; it is a vast burning sea, throwing forth immense flames.
–Revelations given to St. Frances of Rome
“The same fire torments the damned and purifies the elect.”
–Pope St. Gregory the Great
As to the suffering, it is equal to that of Hell.
–St. Catherine of Genoa
Almost all theologians teach that the damned in Hell and the souls in Purgatory, suffer the action of the same fire.
–St. Robert Bellarmine
The souls are in a continual union with God … They are perfectly resigned to His will, or rather their will is so transformed into that of God, that they cannot will but what God wills; so that if Paradise were to be opened to them, they would throw themselves into Hell, rather than appear before God with the stains with which they see themselves disfigured. They purify themselves willingly and lovingly, because such is the Divine good pleasure. …
They wish to be there in the state wherein God pleases, and as long as it shall please Him. “Their bitterest anguish is soothed by a certain profound peace. It is a kind of Hell as regards the suffering; it is a Paradise as regards the delight infused into their hearts by charity – Charity, stronger than death and more powerful than Hell; Charity, whose lamps are all fire and flame. Happy state! More desirable than it is appalling, because its flames are flames of love and charity.
–From Chapter IX of The Spirit of St. Francis de Sales
There is no peace to be compared with that of the souls in Purgatory, except that of the saints in paradise, and this peace is ever increased by the inflowing of God into these souls, which increases in proportion as the impediments to it are removed. The rust of sin is the impediment, and this the fire continually consumes.
– St. Catherine of Genoa