Over the decades of Padre Pio's life millions of souls climbed Mt. Gargano to the Capuchin Friary of Our Lady of Grace to see him and to request his intercession with God. However, according to his own testimony the majority of these souls were not of the living but of the dead. These Poor Souls were those confined to Purgatory for the expiation of the temporal punishment due to their forgiven sins. The Church teaches that while the merits of Christ satisfies the debt of eternal punishment (hell) due to sins for which we have repented, confessed and been forgiven, if contrition and interior conversion is incomplete on our part there remains a satisfaction in the temporal order (in time) to restore the order of justice, especially within us, holiness (Rev 21:27, Mt.5:25-26, 1 Pt. 3:19, 1 Cor. 3:13-15, 2 Macc. 12:42-46). This satisfaction of the temporal debt for sin of the just man is either completed in this life or completed before entering heaven by a proportionate stay in the purifying fires of purgatory. For the damned, unfortunately for them, it is part of their eternal punishment to experience fire unconsoled by the love of God (Mt 12:32, Mt 13:40-42), whereas, for the Poor Souls it is only temporary and they bear it willingly with divine consolation.
However, they long to have this trial completed and to be with God. Unable to merit anymore (Heb. 9:27, Mt. 5:25-26) they desire the just on earth to offer prayers and supplications on their behalf (2 Macc. 12:42-46). Through the communion of saints one part of the Body of Christ (the Church Militant, or just on earth) may console another part of the Body (the Church Suffering or just in Purgatory). The lives of saints and mystics are filled with accounts of God permitting Poor Souls to seek the prayers of the living, whether of family members who may have forgotten them, but usually the holier members of the Church. In Padre Pio's case there was a veritable inundation of souls seeking his prayers and sufferings to be offered to God on their behalf.