If one dies in God’s grace, but has debts to expiate for the sins he has committed and still has defects from which he has to liberate himself in order to enter heaven all pure, he goes to Purgatory to free himself of such debts and defects.
It is precisely for this that Purgatory exists—a temporary kingdom of the life beyond. All those who die in friendship with God, but are not yet pure and worthy of Paradise, go to that place of painful purification for the whole time necessary to purify themselves.
This is why we offer suffrages and pray for the souls in Purgatory: to hasten their passage from that place of pain to the blessed Kingdom of eternal Paradise. (to be continued)