In early 2000s
A baby is born, unfortunately it was on the verge of dead. The doctors did everything they can too save it but he never woke up.
The parent of the baby kept hoping and praying. The baby was always on the verge of death and needed 24/7 surveillance to stop it from completeinf dying off. The technology at that time couldn't save the baby but could stop it from dying.
While the baby was in a coma, it awakens in to an unbelievable situation. It awaken in the afterlife and moments later another soul drifted towards and the baby's soul and merge with it.
It turns out that the other soul came from a parallel universe in which the time was several decade later.
For 19 years the baby/soul were in a coma, he finally awakens.
During these 19 years the soul experience everything the immaterial world had to offer. During his time on the edge of death he draw every area of the afterlife.
Under the golden river was the real material world. The golden river itself represents timeline and reincarnation as well as limbo(the place between life and death). Above that is the stairway to heaven which is where souls go to heaven or fall back to the river for reincarnation.
Above the golden river, the sky is folded with golden cloud which are souls of the dead dreaming of a perfect world and interacting with each other, when they fulfill all their dreams the fall back down the river for reincarnation.
The golden river also serves as a hell or the cleansing. Every sin which is committed in the material world stains the soul with the karma and resentment of the victims. For example if you wrong someone the resentment stain the soul and depending on the degree, when you die and go through the golden river. You will be cleanse by it with excruciating pain and nightmare.
This is the reason why criminals and killers take decade and hundreds of years of hell to reach the afterlife while the souls of baby's go through with ease.
If you stay in the golden river for too long which represent how much sins you committed you are reborn into lesser being such as prey spending your entire next life fearing and running away from predators.
From above the golden ocean, he could go to different point in time and obverse events of future timeline as well as the branch timelines which happens when decisions are made.
The main character is fortunately or unfortunately the only soul who is aware of all the layers of afterlife. When he woke up again he realize he was in the world of tv and movies.
He experience another life as a physic, he trains his souls to see other souls which is filled with thoughts and memories, he communicate with the living and dead and is a messenger between the two worlds.
Later he create a new religion from his experience base off of 4 iron rules to live by.
Never be cruel
Never be cowardly
Be kind
Have compassion
These iron rules will help collect good karma and open the way to heaven. He will face challenges when he stars a new religion from others and he will prove himself.
…
Because he could control his soul so well he could control his Brody well, he could command his brain to increase testosterone to decrease the need to workout to keep in shape, he can increase blood flow to increase strength and stamina.
Anyway these are just ideas and thoughts I had on a whim