Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 12. The Development of Catholic Theology in Conflict with Heresy” Sections 137-158, Loc. 18758-20235.
§ 156. Between Death and Resurrection.
Schaff trenchantly observes that it “is difficult to conceive of a disembodied state of happiness or woe without physical organs for enjoyment and suffering” (Schaff 2014, Loc. 20019). This is exactly the problem we face when discussing death of the body but the soul living on apart from the body as we await the resurrection. For this reason different church fathers took various views about the consciousness of the soul before the resurrection. By the time of the Nicene and the post-Nicene fathers, Schaff finds the folliwing ideas articulated.
Those trusting in God before Christ were held, waiting, until Christ appeared after his death to move them to paradise (Schaff 2014, Loc. 20033). Christian martyrs and others of eminence went immediately to paradise. Most Christians rest in a place of happiness while their remaining sin erodes at which time they reach paradise (Schaff 2014, Loc. 20041). Those who are impenitent or unbelievers go to lower regions for misery before the finan judgment. Those who were pagans or unbaptized were assumed to be judged in some way we do not fully understand (Schaff 2014, Loc. 20055). Because of “the idea of the imperfection of the middle state and the possibility of progressive amelioration” (Schaff 2014, Loc. 20057) it became common to pray for the departed, though that custom is not supported in Scripture. This custom appears in liturgies after the fourth century (Schaff 2014, Loc. 20064). Schaff notes that this cluster of beliefs led to the idea of Purgatory, a middle state which leads eventually to paradise.