Burying and allowing the body to decompose is the wisest option, thus it has become the religious custom.
Are all the deceased imprisoned in the grave?
The deceased are in two groups:
The first are the martyrs who have given their lives up for the sake of Allah, and the saints (walis) who have experienced the mystery of “dying before death”. After they enter the grave and are called to account by the angels they are released to roam about freely until Doomsday.
The second group is further divided into the believers, who will suffer for a period before they are shown their place in paradise and put to sleep until doomsday, and the unbelievers, who also suffer for a period and then shown their place in hell before being out to sleep to see nightmares until doomsday.
When one experiences death and is left alone in the grave with his holographic spirit body he will be subject to immense suffering. Why?
Think about it... Under normal conditions you live your daily life with your biological body but when you see a nightmare you are terrified. It is not your biological body that is terrified, it is your spirit, or magnetic-radial body.
Your conscious mind has no effect while your dreaming, you don’t feel like you are physical body in your dreams you feel more like your magnetic body.
And hence your nightmare gives you a hellish experience. Even though your physical body is sleeping in a comfortable bed untouched by it all.
Usually our dreams are affected by our conditioning, the cosmic effects we receive, our thoughts and emotions… depending on these we either see nice dreams or nightmares.
“SLEEP IS THE BROTHER OF DEATH!”
A part of life after death is of this kind.
All of the active qualities in your brain that you are aware or unaware of are uploaded to your astral body or spirit!
Your life after death will continue with your spirit body at the level of your consciousness at that very last instant just before you die.
You will begin to see all the things that you were veiled from seeing while alive due to the limitations of bodily senses. Your sight will become clear.
You will see clearly the conditions you are subject to, what you will live in the future, and the end of the world!
And you will realize that you have failed to develop and attain certain powers that you should have during your worldly life. And there is no way of having access to your brain, the loading machine which was your only tool to load those powers to your spirit.
A spirit can only be developed by its own brain; no other brain can upload any qualities to it.
So, when you die and your brain stops working you can no longer upload new forces and qualities to your spirit.
Your stuck with what you have. Forever.
This realization then will bring about such immense remorse that it is not possible to describe this pain.
You have an infinite life ahead of you and no way of attaining any other new skill, tool, power, or ability!
And thus, your new life begins.
But you are unable to shape or channel this life, just like when you are in a dream.
You are totally and automatically subject to the conditions of your new life without the ability to change anything because you haven’t attained the necessary powers to do so!
Welcome to endless nightmares to which you haven’t prepared yourself!
This is the suffering of the grave!
This is why the Rasul of Allah (saw) says,
“When the person is buried in his grave, he will scream with such agony that all of the beings, other than humans and the jinn, will hear it!”
To top it off, he will constantly be shown his place in hell and told “this is where you are going to go” and then he will be shown paradise and told, “this is what you missed out on” deepening his suffering.
This is the situation of the common people.
If he is a believer, on the other hand, if he has engaged in certain practices and prepared himself for the afterlife, he will be shown his place in paradise where he will go, and he will also be shown hell and told “this is what you have been saved from!”
He will be told, “this is where you could have gone but your preparative practices have exempt you from it!”
So far, I have been talking about the states of hell and heaven in the grave. Not the actual heaven and hell.
I will discuss them in detail later.
Now there is also another group in the intermediary realm. Those who have attained certain spiritual power… the Saints…
These noble beings are those who have reached and experienced their essential reality, have changed their compositions and have discovered their divine potentials to activate certain spiritual powers!
They will be able to interact with one another during this phase. They will come together and converse with one another. They will share their insights with one another and have discussions.
This realm also has an administrative system and these souls will be trained and recruited for certain activity. On earth, there is a hierarchy of administrators in the intermediary realm referred to as the 4’s, the 7’s, the 12’s and the 40’s, there is an active administration in the afterlife as well.