Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
quran:74:53

No! But they do not fear the Hereafter.  

No indeed! (kallā: a deterrent of what they desire). Rather they do not fear the Hereafter, that is, the chastisement thereof.
القرآن:٧٤:٥٣

كَلَّا ۖ بَلْ لَا يَخَافُونَ الْآخِرَةَ  

{كلا} ردع عما أرادوه {بل لا يخافون الآخرة} أي عذابها.