Final Theosis

Bad news, you're dead.
The second you wake up, you find yourself surrounded by ghosts who, like you, are waiting for their turn to cross the border between Purgatory and Heaven.
Albeit a soul whose memories of your last day as a living person are missing, your job now is to uncover the truth about your demise and help human beings on Earth in order to earn Graces. By doing so, you may be granted a chance to go to your final resting place.

Final Theosis is a daring take at the concept of Purgatory.