Non-Catholics say that purgatory is an invention of the Catholic Church. This is not supported by evidence. Those who say the word purgatory is not in scripture are correct. Purgatory is a state of purification, where the soul has repented of its sins, but which have not been full expiated. At death one s soul goes to heaven if fit for heaven, purgatory if not ready for heaven but not worthy of hell, or to hell if not fit for heaven.
Purgatory is a temporary state.
All souls that go to purgatory will eventually go to heaven. On Judgment Day, there will only be a heaven and a hell. Purgatory will cease to exist. When we die, we will have an individual judgment. We are judged instantly and will receive our reward, good or bad.