One must believe in the torture of the grave. The accountable non-believer who dies without repenting from his blasphemy will be tortured in his grave. Among the torture in the grave for the blasphemer is:

●       seeing Hellfire twice a day, once at the beginning of the day and once at the end of the day,

●       the grave squeezing him until his ribs overlap,

●       the two angels Munkar and Nakir hitting him between his ears with an iron hammer,

●       and other types of torture.

Some of the Muslim sinners, who died without repenting, will be tortured in their graves, with lesser torture than that of the blasphemers. This torture includes being bothered by the darkness and the loneliness in the grave, for example

The one who denies the torture of the grave commits blasphemy. Allah ta^ala said: in Surat Ghaafir verse #46:

﴿ النار ُ يُعرَضون عليها غدوّاً وعشياً ويوم تقوم الساعة أَدخلوا آل فرعون أشد العذاب﴾ سورة غافر

The verse means: [The Fire, they are exposed to it morning and evening. And the Day of Judgement, “Make the people of Pharaoh enter the severest punishment.”]

The Prophet, salla-l-lahu ^alayhi wa sallam,  said:

“إن العبد إذا وضع في قبره وتولى عنه أصحابه إنه ليسمع قرع نعالهم إذا انصرفوا أتاه ملكان فيقعدانه فيقولان: ما كنت تقول في هذا الرجل محمد؟ فأما المؤمن فيقول: أشهد أنه عبد الله ورسوله، فيقال له: أنظر إلى مقعدك من النار أبدلك الله به مقعداً من الجنة، فيراهما جميعاً، وأما الكافر أو المنافق فيقول: لا أدري كنت أقول ما يقول الناس فيه، فيقال لا دريت ولا تليت، ثم يضرب بمطرقة من حديد بين أذنيه فيصيح صيحة يسمعها من يليه إلا الثقلين”. رواه البخاري ومسلم

Which means: “When a human being is laid in his grave and his companions leave, while he still hears their footsteps, two angels come to him and make him sit and ask him: “What did you use to say about this man, Muhammad?” The believer will say: “I bear witness that he is the slave of Allah and His Messenger.” Then it will be said to him: “Look at your place in the Hellfire. Allah has given you a place in Paradise instead of it.” Then he will see both his places. But a non-believer or a hypocrite will reply to the question of the angels: “I do not know, but I used to say what the people used to say!” It will be said to him: “Neither did you know nor did you give the right answer.” Then he will be hit with an iron hammer between his two ears, and he will cry, and that cry will be heard by whatever approaches him, except human beings and jinns,” narrated by al-Bukhariyy and Muslim, as related by Anas from the Prophet, salla-l-lahu ^alayhi wa sallam.