It seems like everyone has forgotten a very important thing about purgatory, and getting out!
The primary way to get out of Catholic purgatory (thankful I am Protestant!) is for the relatives of the dead person to buy masses for the dead. The more masses, the quicker the loved one gets out of purgatory.
My grandmother was French during WWI, near the front lines. She could hear the guns booming in the distance. The children were emaciated and starving. So, instead of the life time plan of buying masses for their dead loved ones, they chose to use the little amount of money they had, to buy food for the children. My grandmother totally turned away from God, after seeing how callous the priests were, and how they twisted and manipulated the people to give money for masses. Meanwhile, the Vatican continued to have gold doors, and suck up money from people. I guess things haven't changed a lot from the days of indulgences, just a different money making scheme!
I remember at my Catholic uncle's funeral, a close friend and Lutheran, along with the man's son, a Baptist, took out the prayers for the dead from the service (ie mass). The priest got really angry when he saw it was gone, and said, "Surely this man committed sins that were not forgiven before he died. He needs prayer to get out of purgatory."
Which moves us to the subject of Catholic soteriology, as opposed to Protestant! Protestants believe God saves us (either with our help - synergism, or without our help monergism), and then the Holy Spirit sanctifies us till the day we die, after which comes glorification. In other words, we can KNOW we are saved!
Catholics believe they have to earn their sanctification, through works, good deeds, and I suppose the 7 sacraments. They cannot know they if they are saved or not, no matter what they do. It is a pay for salvation system, if ever there was one.
So, if you can't know if you are saved, you really do need a place to go, to keep you out of hell. Except, that no such place exists in the Bible. As for the OPs little twisted scripture, neither clear enough or often enough to make a doctrine out of it. Let alone venial and mortal sins, also not in the Bible.
It kind of makes me wonder why on earth they bother with Jesus at all? If Jesus' once for all sacrifice, as the perfect Lamb of God was not enough, no amount of masses is going to get any dead person out of purgatory. I was reading an article today by RC Sproule about double predestination. He talked about the option of universal reprobration, which nobody believes. Well, thinking about this thread, and the Catholic Church, I think RC got it wrong! The Catholic Church puts 99.9% of its followers in a hell called purgatory, which they can never get out of. If that isn't universal reprobation, I don't know what is!
"But when this priest [Jesus] had offered for all time one sacrifice for sins, he sat down at the right hand of God, 13 and since that time he waits for his enemies to be made his footstool. 14 For by one sacrifice he has made perfect forever those who are being made holy." Hebrews 10:12-14.
