Praise be to Allah.
The Grave is not a joke, and Muslims should take it serious by performing their righteous deed, because of the questioning in the grave.
Shaykh Muhammad ibn ‘Uthaymeen (may Allaah have mercy on him) said:
The questioning of the deceased in the grave is undoubtedly real, and the person sits up in his grave, speaks and is questioned.
However, if someone said the grave is narrow and confined, so how can he sit up?
Here is the answer, no one asks about how or why except the one who has doubts. So with regard to matters of the unseen, the believer is required to accept them and believe, and not ask how or why.
But the one who believes and whose heart is content with what Allaah and His Messenger say, will accept it and say, Allaah knows best about how that happens.
When a person dreams, he sees himself coming and going, travelling, speaking to people, meeting people both living and dead.
But the connection of the soul to the body after death is different to its connection when one is awake and when one is asleep. It is different and we do not understand it. So a person can sit up in his grave and be questioned, even though the grave is narrow and confined.
In conclusion, however, the question of the grave is real and true, and one must not be against it.
“But no, by your Lord, they can have no Faith, until they make you (O Muhammad) judge in all disputes between them, and find in themselves no resistance against your decisions, and accept (them) with full submission”
And Allah knows best.