Encyclopædia Britannica: Purgatory in world religions: "The idea of purification or temporary punishment after death has ancient roots and is well-attested in early Christian literature. The conception of purgatory as a geographically situated place is largely the achievement of medieval Christian piety and imagination."
"There are three categories of men; the wholly pious and the arch-sinners are not purified, but only those between these two classes" (Jewish Encyclopedia: Gehenna)
Question 201 of Luther's Small Catechism with Explanation (Concordia Publishing House, 1991 edition) answers the question "For whom should we pray?" as follows: "We should pray for ourselves and for all other people, even for our enemies, but not for the souls of the dead" (Soul Sleep – Wisconsin Evangelical Lutheran SynodArchived 2009년 6월 28일 - 웨이백 머신 참고)
Question 201 of Luther's Small Catechism with Explanation (Concordia Publishing House, 1991 edition) answers the question "For whom should we pray?" as follows: "We should pray for ourselves and for all other people, even for our enemies, but not for the souls of the dead" (Soul Sleep – Wisconsin Evangelical Lutheran SynodArchived 2009년 6월 28일 - 웨이백 머신 참고)
