You perhaps did not consider that "eternity" means a state that is everlasting, without end. It's you know, "eternal". A purification process which has a beginning and an end cannot happen in an eternal state, by definition.
Purgatory is not eternal.
Bedtime for me. Good night and God bless you, aMPU.
"A purification process which has a beginning and an end cannot happen in an eternal state, by definition."
We'll have to disagree. We see many things in Revelation that have a beginning and end.
Many blessings to you Mrs. Don-o