Luther is talking about purgatory quite often in the Ninety-Five Theses. Let’s consider what the Roman Catholic Church was teaching concerning purgatory.
The idea that purgatory is a physical place of fiery punishment where you must “purge” any results of your sin before you go to heaven is developed in the Roman Catholic Church by the 11th century. The Catholic Church believed that the living can help those whose purification from their sins is not yet completed not only by praying for them but also by gaining indulgences for them as an act of intercession.
There is no biblical support for the doctrine of Purgatory. The Roman Catholic Church added books to their Bible that are between the Old and New Testaments, called, “The Apocrypha,” where there is an example pf praying for the dead that they may have sins forgiven after they are dead (2 Maccabees 12:41-46). ” Luther included these books in his Bible translation separately but did not consider them Scripture. He said “these are books which are not consider equal to the Holy Scriptures, but are useful and good to read.”
The Nine-Five Theses are written in 1517 and Luther still thinks there is a purgatory. He will change his thinking within the next ten years. In the 1522 version of Luther’s Personal Prayer Book he has this petition: “Have mercy upon all poor souls in purgatory.” In his 1524 edition of the same book this petition is taken out. Formally, Luther rejects purgatory in 1528 in his writing, Confession Concerning Christ’s Supper.
OK, now let’s look at Theses 11-20
11) Those tares of changing the canonical penalty to the penalty of purgatory were evidently sown while the bishops slept (Mt 13:25).
The parable of the wheat and tares concerns an enemy of a farmer who plants weeds (tares) amongst the good seed (wheat). Luther is saying there is no basis for teaching punishment for sin after death. It must have become Catholic teaching while those who oversee the teaching were sleeping (a bit of Luther’s sarcasm).
12) In former times canonical penalties were imposed, not after, but before absolution, as tests of true contrition.
13) The dying are freed by death from all penalties, are already dead as far as the canon laws are concerned, and have a right to be released from them.
The dead can’t be held to earthly ways of dealing with punishment for sin once they are dead.
14) Imperfect piety or love on the part of the dying person necessarily brings with it great fear; and the smaller the love, the greater the fear.
15) This fear or horror is sufficient in itself, to say nothing of other things, to constitute the penalty of purgatory, since it is very near to the horror of despair.
It is penalty enough for those who dying that they are in despair concerning the torment of purgatory. You don’t need to add other penalties on top of this.
16) Hell, purgatory, and heaven seem to differ the same as despair, fear, and assurance of salvation.
Hell brings despair, purgatory brings fear, and heaven brings assurance. You can see where this way of thinking is going to lead Luther when he no longer holds to the doctrine of purgatory. In dying there is pure grace and assurance.
17) It seems as though for the souls in purgatory fear should necessarily decrease and love increase.
Why would those in purgatory have an increase in fear when supposedly they are being “purged” of their sin?
18) Furthermore, it does not seem proved, either by reason or by Scripture, that souls in purgatory are outside the state of merit, that is, unable to grow in love.
It is not proven in Scripture that there is a purgatory, but if there is then love ought to increase during people’s in-between time.
19) Nor does it seem proved that souls in purgatory, at least not all of them, are certain and assured of their own salvation, even if we ourselves may be entirely certain of it.
How do those in purgatory know the penalty for their sins are being lessened or purged clean by the action of the living who are praying for them and using indulgences?
20) Therefore the pope, when he uses the words “plenary remission of all penalties,” does not actually mean “all penalties,” but only those imposed by himself.
If God is imposing penalties after death, only God can redeem people from these penalties. The pope can’t.