Answer: - From Hazrat Adam to Hazrat Muhammad, all the followers say that after death everyone will be buried in the graves. When Judgement Day (dissolution) arrives, everyone will be resurrected. Then those who are virtuous will reside in heaven and the sinners will live in hell forever. This theory is rejected by Hazrat Muhammad ji's journey to the heavens (Meraj) when he sees everyone from Baba Adam to Hazrat Isa in heaven. In fact, it is the Pitar Lok which is in the middle of Heaven and Hell. There is happiness and sorrow there just like on earth.
The reality is this: - There is an episode in Shiv Puran that once Shiv ji takes his wife Parvati to a secluded place to give her initiation. They sit down near a withered tree. The initiation-mantra must be recited only to a deserving person. Shiv ji clapped his hands three times. It produced a horrific sound, fearing which all the animals and birds went away. Burrow-like holes were present in the trunk of that dry tree, which are usually found in the trunk of old trees, that are formed by the infestation of termites etc. A female parrot had laid eggs in the hollow of the trunk of that tree. The eggs that were healthy hatched and parrots flew away from them.
One egg had become spoilt; it remained there. There was a living being in every egg. The living being of the spoilt egg was still in it. When Shiv ji was convinced that there was no creature around to listen to them, he started narrating the glory of the Supreme God to his wife Parvati and explaining the subject of lotuses (the lotus chakras formed in the body). He also started telling the mantra to open each lotus. After listening to every mantra, Parvati ji used to indicate acceptance of everything by saying ‘(haan… hoon) yes... okay’. After some time, Parvati ji dozed off. At that time, the sound of ‘(haan… hoon) yes… okay’ started coming from the hollow of the tree because the story of God is more effective when heard from a person worthy of reciting it. Due to which, the spoilt egg of the parrot became healthy, and a bird formed in it. The parrot bird had started making sounds. Shiv ji saw that Parvati was not speaking. “Then who is doing ‘(haan… hoon) yes… okay’? Somebody has overheard my immortal mantra. It should be killed.” Seeing Shiv ji get up, the parrot flew away, and leaving the body of the parrot, it went into the stomach of the wife of Sage Ved Vyas. At that time, Vyas ji's wife had opened her mouth to yawn. The soul of the parrot had gone into the stomach through the mouth. It remained in the womb for twelve years. Then it took birth in the form of Sage Sukhdev. This is a long story. Now let me return to the topic. The discussion going on is “whether a soul resides in the grave or not".
One who has got the body of a human (male or female), if after taking refuge in a Satguru (true spiritual teacher), he/she (bhakti) worships and performs meritorious and noble deeds, then after death, he/she goes to the higher worlds according to the deeds. The devotee (male or female) of Kabir ji goes to Satlok. Others, who do not (bhakti) worship or do wrong worship, after death they also according to their deeds go to hell or to the bodies of other beings. Some living beings have such bad deeds that they do not get any body soon. They obtain the life of a ghost. The living beings, who do not get the next body, live near their old body by being entrapped in its attachment. As the body in which the living being lives is very dear to him, due to this sentiment, those beings live with their bodies buried in the graves. They reside on top of that grave. If an ant makes a hole, they go through it and stick to their body. Sometimes they come out. Until they get a new body, they cling to the old body because of their attachment to it.
In Hindu religion, after cremating the dead body, the remaining pieces of bones (which are called ashes) are picked and immersed in the deep water of a river, so that if the family member, who has died, has become a ghost, then clinging to those remains of the body (remnants of bones), he/she will go far away. He/she will not bother us. The topic going on was whether a living being lives in graves or not. It has been clarified that only those beings live in the graves, who have got the life of a ghost or a Jinn. Due to which, they have not obtained further body. For evidence, the soul of the parrot was clinging to the spoiled egg. It was considering it to be its own. Similar is the condition of the living beings associated with the graves. They reside on the graves as ghosts. After getting a new body, the living being of that corpse does not remain in the grave.