The proponents of purgatory say it has roots that date back into antiquity. A sort of proto-purgatory called the "celestial Hades" appears in the writings of secular philosophers, including Plato, and Heraclides Ponticus, and many other Classical writers. This concept is distinguished from the Hades of the underworld described in the works of Homer and Hesiod. In contrast, the celestial Hades was understood as an intermediary place where souls spent an undetermined time after death before either moving on to a higher level of existence or being reincarnated back on Earth. Its exact location varied from author to author: Heraclides Ponticus thought it was in the Milky Way; the Academicians, the Stoics, Cicero, Virgil, Plutarch, and Hermetical writings situated it between the Moon and the Earth or around the Moon; while Numenius and the Latin Neoplatonists thought it was located between the sphere of the fixed stars and the Earth.Adrian Mihai,"L'Hadès céleste. Histoire du purgatoire dans l'Antiquité" (Garnier: 2015), pp. 185–188

Perhaps under the influence of Hellenistic thought, the intermediate state entered Jewish religious thought in the last centuries B.C.E. In Maccabees is found prayer for the dead, with a view to their afterlife purification,cf. a practice accepted by some Christians. This same practice appears in other traditions, such as medieval Chinese Buddhist practices of making offerings on behalf of the dead, who are said to suffer numerous trials.Purgatory in Encyclopædia Britannica Among other reasons, the Catholic Church's teaching of purgatory is based on the Judaic practice.Catechism of the Catholic Church, 1032

Descriptions and doctrine regarding purgatory developed over the centuries.Isabel Moreira, Heaven's Purge (Oxford University Press, 2010) pp. 3–13 Roman Catholics who believe in purgatory interpret New Testament passages such as , , , and as supporting prayer for souls who are believed to be alive in an active, interim state after death, undergoing purifying flames (which could be interpreted as analogy or allegory) until they are cleansed and admitted into Heaven. Early Christians did not develop consistent and universal beliefs about such an interim state. Some modern speculation also includes as support for the concept of purgatory, but through the ages the Church has taught that the rich man of the parable had already received his final judgment,St. John Chrysostom, Hom on 1 Cor and the text itself refers to a chasm which may not be crossed. Gradually, Christians, especially in the West, took an interest in circumstances of the interim state between death and the future resurrection. Christians in both East and West prayed for the dead in this interim state, although theologians in the East refrained from defining it as a physical location with a distinct name. Augustine of Hippo distinguished between the purifying fire that saves, and the eternally consuming fire for the unrepentant. Gregory the Great established a connection between earthly penance and purification after death. All Soul's Day, established in the 10th century, turned popular attention to the condition of departed souls.

While the idea of Purgatory as a physical place (like heaven and hell) became a theological opinion among some Roman Catholic theologians teaching in the late 11th century; the concept of Purgatory being a physical reality has never been a part of Catholic doctrine.Jacques Le Goff, The Birth of Purgatory (University of Chicago Press, 1984) Mediaeval theologians concluded that purgatorial punishment consisted of material, literal fire. The Western formulation of purgatory proved to be a sticking point in the Great Schism between East and West. The Roman Catholic Church believes that the living faithful can help souls complete their purification from sins by praying for them, and by gaining indulgences for themCCC, 1479 as an act of intercession.Cross, F. L., ed., The Oxford Dictionary of the Christian Church (Oxford University Press 2005), article indulgences The Late Middle Ages saw the growth of considerable abuses, such as the unrestricted sale of indulgences by professional "pardoners" sent to collect contributions to projects such as the rebuilding of Saint Peter's Basilica in Rome. These abuses were one of the factors that led to the Protestant Reformation, with most Protestant groups today rejecting the idea of purgatory as it conflicted with the doctrine of "Salvation by grace alone" (). Luther's canon of the Bible excluded the Deuterocanonical books. Modern Catholic theologians have softened the punitive aspects of purgatory, and instead stress the willingness of the dead to undergo temporary purification as preparation for the everlasting joys of heaven.

The English Anglican scholar John Henry Newman argued, in a book that he wrote before converting to Catholicism, that the essence of the doctrine on purgatory is locatable in ancient tradition, and that the core consistency of such beliefs are evidence that Christianity was "originally given to us from heaven".John Henry Newman, An Essay on the Development of Christian Doctrine, chapter 2, section 3, paragraph 2.

Christian Antiquity

Prayer for the dead

Prayers for the dead were known to ancient Jewish practice, and it has been speculated that Christianity may have taken its similar practice from its Jewish heritage.George Cross, "The Differentiation of the Roman and Greek Catholic Views of the Future Life", in The Biblical World (1912) p. 106 In Christianity, prayer for the dead is attested since at least the 2nd century,Gerald O' Collins and Mario Farrugia, Catholicism: the story of Catholic Christianity (Oxford: Oxford University Press, 2003) p. 36; George Cross, "The Differentiation of the Roman and Greek Catholic Views of the Future Life", in The Biblical World (1912) p. 106; cf. Pastor I, iii. 7, also Ambrose, De Excessu fratris Satyri 80 evidenced in part by the tomb inscription of Abercius, Bishop of Hierapolis in Phrygia (d. c. 200).Gerald O' Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 217 Celebration of the Eucharist for the dead is attested to since at least the 3rd century.Gerald O' Collins and Mario Farrugia, Catholicism: the story of Catholic Christianity (Oxford: Oxford University Press, 2003) p. 36; George Cross, "The Differentiation of the Roman and Greek Catholic Views of the Future Life", in The Biblical World (1912) p. 106

Purification after death Specific examples of belief in purification after death and of the communion of the living with the dead through prayer are found in many of the Church Fathers.Gerald O'Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 27. Irenaeus (c. 130–202) mentioned an abode where the souls of the dead remained until the universal judgment, a process that has been described as one which "contains the concept of... purgatory."Christian Dogmatics vol. 2 (Philadelphia : Fortress Press, 1984) p. 503; cf. Irenaeus, Against Heresies 5.31.2, in The Ante-Nicene Fathers eds. Alexander Roberts and James Donaldson (Grand Rapids: Eerdmans, 1979) 1:560 cf. 5.36.2 / 1:567; cf. George Cross, "The Differentiation of the Roman and Greek Catholic Views of the Future Life", in The Biblical World (1912) p. 107 Origen of Alexandria (c. 185-254), developed a view of purification after death;Gerald O'Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 27; cf. Adolph Harnack, History of Dogma vol. 2, trans. Neil Buchanan (London, Williams & Norgate, 1995) p. 337 this view drew upon the notion that fire is a divine instrument from the Old Testament, and understood this in the context of New Testament teachings such as baptism by fire, from the Gospels, and a purificatory trial after death, from St. Paul.Jacques Le Goff, The Birth of Purgatory (University of Chicago Press, 1984) p. 53; cf. , , Origen, in arguing against soul sleep, stated that the souls of the elect immediately entered paradise unless not yet purified, in which case they passed into a state of punishment, a penal fire, which is to be conceived as a place of purification.Adolph Harnack, History of Dogma vol. 2, trans. Neil Buchanan (London: Williams & Norgate, 1905) p. 377. read online. For Origen, the fire was neither a material thing nor a metaphor, but a "spiritual fire".Jacques Le Goff, The Birth of Purgatory (University of Chicago Press, 1984) pp. 55–57 An early Latin author, Tertullian (c. 160–225), also articulated a view of purification after death.Gerald O'Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 27; cf. Adolph Harnack, History of Dogma vol. 2, trans. Neil Buchanan (London, Williams & Norgate, 1995) p. 296 n. 1; George Cross, "The Differentiation of the Roman and Greek Catholic Views of the Future Life", in The Biblical World (1912); Tertullian De Anima In Tertullian's understanding of the afterlife, the souls of martyrs entered directly into eternal blessedness,A. J. Visser, "A Bird's-Eye View of Ancient Christian Eschatology", in Numen (1967) p. 13 whereas the rest entered a generic realm of the dead. There the wicked suffered a foretaste of their eternal punishments, whilst the good experienced various stages and places of bliss wherein "the idea of a kind of purgatory… is quite plainly found," an idea that is representative of a view widely dispersed in antiquity.Adolph Harnack, History of Dogma vol. 2, trans. Neil Buchanan (London: Williams & Norgate, 1905) p. 296 n. 1. read online; cf. Jacques Le Goff, The Birth of Purgatory (University of Chicago Press, 1984) pp. 58–59 Later examples, wherein further elaborations are articulated, include St. Cyprian (d. 258),Cyprian, Letters 51:20; Gerald O'Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 27 St. John Chrysostom (c. 347–407),John Chrysostom, Homily on First Corinthians 41:5; Homily on Philippians 3:9–10; Gerald O'Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 27 and St. Augustine (354–430),Augustine, Sermons 159:1, 172:2; City of God 21:13; Handbook on Faith, Hope, and Charity 18:69, 29:109; Confessions 2.27; Gerald O' Collins and Mario Farrugia, Catholicism: the story of Catholic Christianity (Oxford: Oxford University Press, 2003) p. 36; Gerald O'Collins and Edward G. Farrugia, A Concise Dictionary of Theology (Edinburgh: T&T Clark, 2000) p. 27 among others.

Interim state

The Christian notion of an interim state of souls after death developed only gradually. This may be in part because it was of little interest as long as Christians looked for an imminent end of the world, as many scholars believe they did. The Eastern Church came to admit the existence of an intermediate state, but refrained from defining it, while at the same time maintaining the belief in prayer for the dead that was a constant feature of both Eastern and Western liturgies, and which is unintelligible without belief in an interim state in which the dead may be benefited. Christians in the West demonstrated much more curiosity about this interim state than those in the East: The Passion of Saints Perpetua and Felicity and occasional remarks by Saint Augustine give expression to their belief that sins can be purged by suffering in an afterlife and that the process can be accelerated by prayer.Oxford Dictionary of the Christian Church (Oxford University Press 2005 ), article Purgatory