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.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
abudawud:594 – Aḥmad b. Ṣāliḥ > Ibn Wahb > Muʿāwiyah b. Ṣāliḥ > al-ʿAlāʾ b. al-Ḥārith > Makḥūl > Abū Hurayrah

The obligatory prayer is essential behind every Muslim, pious or impious, even if he has committed a sins.  

أبو داود:٥٩٤ – حَدَّثَنَا أَحْمَدُ بْنُ صَالِحٍ حَدَّثَنَا ابْنُ وَهْبٍ حَدَّثَنِي مُعَاوِيَةُ بْنُ صَالِحٍ عَنِ الْعَلاَءِ بْنِ الْحَارِثِ عَنْ مَكْحُولٍ عَنْ أَبِي هُرَيْرَةَ قَالَ

قَالَ رَسُولُ اللَّهِ ﷺ الصَّلاَةُ الْمَكْتُوبَةُ وَاجِبَةٌ خَلْفَ كُلِّ مُسْلِمٍ بَرًّا كَانَ أَوْ فَاجِرًا وَإِنْ عَمِلَ الْكَبَائِرَ