You think Hell and Purgatory are the same place. So?
Why don't you cite an Ecumenical Council or something from The Sources of Catholic Dogma or Catechism of the Catholic Church you oppose and then maybe we can have something solid to kick around.
Actually I think a list of councils which mention a place called purgatory (and what they said about it) would go great lengths toward illuminating this discussion...
Why don't I?
Because I don't need to!
Jesus used the word "Gehenna", over and over and over.
Gehenna means something.
It means Hell, to Jews.
SPECIFICALLY, it means the place where souls who have done bad things go, some to be purified and some to remain.
Always did.
We don't need a Church Council to explain, JESUS explained it, by using the Jewish term and not explaining it or modifying it for his Jewish audience. He knew what they thought Gehenna was - Christian Hell AND Purgatory, all at once - and he used that word, and just that word, as an image.
Now, when Jesus wanted to modify something in the Jewish law, like divorce or the giving of gifts to the Temple, he mentioned the Scripture or the Jewish tradition (e.g. "korban"), and then he modified it. But with Gehenna, he did no such thing. He knew what Jews thought Gehenna was: Purgatory/Hell. He used the term straight, without explanation, without modification.
It means what Jesus used it as.
Why would anyone think it didn't?
Truth is, Christians many years later didn't have access to Jews, didn't LIKE Jews, and didn't (and most today don't) know what Jews meant or believed. That Jesus's "Greatest Commandment" is actually The Shema - "Hear, O Israel! The Lord is our God! The Lord is One! And you shall love the Lord, your God, with all your heart, and with all your soul..." etc. is virtually unknown by people of EITHER religion. And yet, Jesus was a Jew talking to Jews. He used Jewish forms and Jewish norms and Jewish words and concepts.
Sometimes he modified them, and there we should sit up and take note.
But sometimes, he DIDN'T, and there too we should sit up and take note, because it tells us that the Jews got it right.
Jesus used Gehenna, he used it to make a severe point. He used it knowing what his audience thought, and he didn't attempt to alter their understanding. That is significant.
It tells ME, the simple reader, that Jesus meant what he said, and what he said meant what it meant. Gehenna means Hell AND Purgatory.
It seems to me that, once one knows this (and one learns this by reading the Jewish literature, to see what THEY mean by it, the Midrash, notably, and commentators all the way back to Josephus). Do that, and one discovers something important: the meaning of the word Gehenna to JEWS. Why would anyone assume that Jesus, a Jew, didn't mean what Jews meant when he used a term like "Sabbath", or "Scriptures", or "korban", or "Sanhedrin", or "Gehenna"?
There is no reason.
If we have piled tradition atop tradition in order to try and explain something which is more simply explained and understood, well, that is our right as creative people. As for me, the simplest explanation that fits the facts is the best explanation, and we should not multiply entities when we need not. Jewish "Gehenna" expresses perfectly the concept that Jesus seems to have been driving at.
Permanent "Hell" does not. Remember the harsh lender, who throttled the poor man who didn't pay him back after he himself was let off the hook by his own overlord, to whom he owed money? He thrown into the deepest dungeon "until every last penny was paid". Which is not at all the same thing as forever. It is, indeed, purgatorial. That's Gehenna.
I am not interested in opposing an Ecumenical Council or the Cathechism of the Catholic Church. I am merely pointed out what Jesus actually SAID, and suggesting that this ought to be the basis for cutting through the fog of misunderstanding on the issue. Purgatory is correct doctrine: it's Gehenna. Hell is correct doctrine: it's Gehenna. Why complicate this?