Sam: Though I’m not a Catholic, I do respect the Catholic Church’s willingness to dispense with some of those old superstitions that arose in the middle-ages, like purgatory and that.
Justin: Um, what?
Sam: Yeah, you know how you all used to believe in purgatory but now that’s been done away with?
Justin: Yeah; sorry to disappoint you but that isn’t true. Purgatory is an infallible teaching of the Church, not an invention of the middle-ages, it’s part of the deposit of faith left to us by Christ and the apostles, it hasn’t been “done away with.”
Sam: Ah, I’m sure I read that somewhere.
Justin: Well as reliable a source as that sounds, I’m telling you it’s false. The Church teaches that, “all who die in God’s grace and friendship, but still imperfectly purified, are indeed assured of their eternal salvation; but after death they undergo purification, so as to achieve the holiness necessary to enter the joy of Heaven” (CCC 1030)
Sam: Fair enough; I stand corrected.
Justin: If you’re a Bible believing Christian, as you claim, you should believe in purgatory as well—of course if you were a Bible believing Christian you should be Catholic, but one step at a time.
Sam: See, now you’re just being condescending.
Justin: A little, but play along. You believe that the Bible is the word of God, yes?
Sam: Yes, Justin, I believe that the Bible is the word of God.
Justin: Good, so you believe, as it says in Revelation, that “nothing unclean shall enter heaven.”?
Sam: Yes, that’s right.
Justin: And what do you think the bible means by “unclean”?
Sam: Well it’s not referring to those who haven’t showered recently; it’s talking about sin. Sin is what makes us unclean.
Justin: And what about attachment to sin? Will we have that in heaven?
Sam: What do you mean “attachment”?
Justin: Say a woman has repented of and ceased committing adultery, but in hear heart she still wants to commit adultery. She no longer commits the sin of adultery but she wishes she could, she’s envious of those who do commit it.
Sam: No, obviously the saved will not experience anything like that in Heaven.
Justin: But isn’t it true, Sam, that a good number of those who will be saved are either sinning or attached to sin at the moment of their death? That they aren’t perfect as their heavenly Father is perfect? That they aren’t clean?
Sam: I’m sorry, Justin. I think your argument is judgmental, and we have been forbidden by our Lord to judge.
Justin: That’s a red herring, Sam. Arguments are not judgmental, people are. Arguments are sound or unsound. How is this argument unsound. 1. The saved will not sin nor be attached to sin in heaven. 2. Many people who will be saved are still sinning or attached to sin at the moment of their deaths. 3. Therefore there must be stage between this life when those who will be saved are unclean and Heaven when those who will be saved are perfectly clean. Catholic call that stage purgatory.
Sam: Your problem, Justin, is that you rely on logic and reason instead of the word of God.
Justin: If the price of protestantism is irrationality, that’s not a price I’m willing to pay. Besides, it’s false that I have not relied on the word of God, I have, and, I think, if you will follow the teachings of the Holy Bible you should believe in purgatory as well. You’re familiar with C.S. Lewis?
Sam: Of course.
Justin: He understood purgatory to be perfectly reasonable. He spoke of if in one of his letters.
Sam: Which one?
Justin: I’m not sure. Let me look it up. Give me a sec. Ah, here it is. He writes:
“Our souls demand purgatory, don’t they? Would it not break the heart if God said to us, “It is true, my son, that your breath smells and your rags drip with mid and slime, but we are charitable here and no one will upbraid you for these things, nor draw away from you. Enter into joy”? Should we not reply, “With submission, sir, and if there is no objection, I’d rather be cleansed first.” It may hurt, you know” — ”Even so sir.”
Sam: Well how long is purgatory supposed to take?
Justin: How should I know? We don’t even know how time works in the afterlife, it might not take any time at all. Cardinal Joseph Ratzinger (now Pope Emeritus Benedict XVI) seemed to side with those theologians who say that purgatory may be the very encountering of God’s love which purifies us and might not take any “time” at all. He wrote, “[Purgatory] is the inwardly necessary process of transformation in which a person becomes capable of Christ, capable of God and thus capable of unity with the whole communion of saints.” 
Sam: I’ll admit it. Purgatory isn’t as crazy an idea as I once thought. I’m not completely sold, but I’m open. Where could I learn more?
Justin: You could read what the Catechism of the Catholic Church has to say about it. At least that way if you disagree with the Catholic Church you’ll disagree about what it is she actually teaches, as opposed to what you’ve heard she teaches. Also, there’s this apologist, Matt Fradd? He’s amazing, and way better looking than that Chris Stefanick character—if you know who he is. Here’s an audio clip of him explaining it in his deliciously delightful Australian tongue:
Sam: … Ah, dude, are you okay?
Justin: I’m fine…sorry. Not sure what came over me.
 Joseph Ratzinger, Eschatology: Death and Eternal Life, p. 230-231