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:64:7

Those who disbelieve have claimed that they will never be resurrected. Say, "Yes, by my Lord, you will surely be resurrected; then you will surely be informed of what you did. And that, for Allah, is easy."  

Those who disbelieve claim that (an is softened, its subject having been omitted, that is to say, annahum) they will never be resurrected. Say: ‘Yes indeed, by my Lord! You will be resurrected; then you will be informed of what you did. And that is easy for God’.
القرآن:٦٤:٧

زَعَمَ الَّذِينَ كَفَرُوا أَنْ لَنْ يُبْعَثُوا ۚ قُلْ بَلَىٰ وَرَبِّي لَتُبْعَثُنَّ ثُمَّ لَتُنَبَّؤُنَّ بِمَا عَمِلْتُمْ ۚ وَذَٰلِكَ عَلَى اللَّهِ يَسِيرٌ  

{زعم الذين كفروا أن} مخففة واسمها محذوف، أي أنهم {لن يبعثوا قل بلى وربي لتبعثن ثم لتنبؤن بما عملتم وذلك على الله يسير}.