"I accompanied the Prophet ﷺ on a journey. One day I was near him while we were moving so I said: 'O Messenger of Allah! Inform me about an action by which I will be admitted into Paradise, and which will keep me far from the Fire.' He said: 'You have asked me about something great, but it is easy for whomever Allah makes it easy: Worship Allah and do not associate any partners with Him, establish the Salat, give the Zakat, fast Ramadan and perform Hajj to the HOuse.' Then he said: 'Shall I not guide you to the doors of good? Fasting is a shield, and charity extinguishes sins like water extinguishes fire - and a man's praying in depths of the night.'" He said: "Then he recited: 'Their sides forsake their beds to call upon their Lord.' Until he reached: 'What they used to do.' [32:16-17] Then he said: 'Shall I not inform you about the head of the entire matter, and its pillar, and its hump?' I said: 'Of course O Messenger of Allah! He said: 'The head of the matter is Islam, and its pillar is the Salat, and its hump is Jihad.' Then he said: 'Shall I not inform you about what governs all of that?' I said: 'Of course O Messenger of Allah!'" He ﷺ said: "So he grabbed his tongue. He said 'Restrain this.' I said: 'O Prophet of Allah! Will we be taken to account for what we say?' He said: 'May your mother grieve your loss O Mu'adh! Are the people tossed into the Fire upon their faces, or upon their noses, except because of what their tongues have wrought'"  

كُنْتُ مَعَ النَّبِيِّ ﷺ فِي سَفَرٍ فَأَصْبَحْتُ يَوْمًا قَرِيبًا مِنْهُ وَنَحْنُ نَسِيرُ فَقُلْتُ يَا رَسُولَ اللَّهِ أَخْبِرْنِي بِعَمَلٍ يُدْخِلُنِي الْجَنَّةَ وَيُبَاعِدُنِي مِنَ النَّارِ قَالَ لَقَدْ سَأَلْتَنِي عَنْ عَظِيمٍ وَإِنَّهُ لَيَسِيرٌ عَلَى مَنْ يَسَّرَهُ اللَّهُ عَلَيْهِ تَعْبُدُ اللَّهَ وَلاَ تُشْرِكُ بِهِ شَيْئًا وَتُقِيمُ الصَّلاَةَ وَتُؤْتِي الزَّكَاةَ وَتَصُومُ رَمَضَانَ وَتَحُجُّ الْبَيْتَ ثُمَّ قَالَ أَلاَ أَدُلُّكَ عَلَى أَبْوَابِ الْخَيْرِ الصَّوْمُ جُنَّةٌ وَالصَّدَقَةُ تُطْفِئُ الْخَطِيئَةَ كَمَا يُطْفِئُ الْمَاءُ النَّارَ وَصَلاَةُ الرَّجُلِ مِنْ جَوْفِ اللَّيْلِ قَالَ ثُمَّ تَلاََ ( تَتَجَافَى جُنُوبُهُمْ عَنِ الْمَضَاجِعِ ) حَتَّى بَلَغَ (يَعْمَلُونَ) ثُمَّ قَالَ أَلاَ أُخْبِرُكَ بِرَأْسِ الأَمْرِ كُلِّهِ وَعَمُودِهِ وَذِرْوَةِ سَنَامِهِ قُلْتُ بَلَى يَا رَسُولَ اللَّهِ قَالَ رَأْسُ الأَمْرِ الإِسْلاَمُ وَعَمُودُهُ الصَّلاَةُ وَذِرْوَةُ سَنَامِهِ الْجِهَادُ ثُمَّ قَالَ أَلاَ أُخْبِرُكَ بِمَلاَكِ ذَلِكَ كُلِّهِ قُلْتُ بَلَى يَا نَبِيَّ اللَّهِ قَالَ فَأَخَذَ بِلِسَانِهِ قَالَ كُفَّ عَلَيْكَ هَذَا فَقُلْتُ يَا نَبِيَّ اللَّهِ وَإِنَّا لَمُؤَاخَذُونَ بِمَا نَتَكَلَّمُ بِهِ فَقَالَ ثَكِلَتْكَ أُمُّكَ يَا مُعَاذُ وَهَلْ يَكُبُّ النَّاسَ فِي النَّارِ عَلَى وُجُوهِهِمْ أَوْ عَلَى مَنَاخِرِهِمْ إِلاَّ حَصَائِدُ أَلْسِنَتِهِمْ  

that the Messenger of Allah ﷺ said: "If you see a man who comes to the Masjid then bear witness to his faith." Because Allah, the Exalted, says: Only those who believe in Allah, and the Last Day, and establish the Salat, and give the Zakat (should) maintain the Masajid until the end of the Ayah (9:18)  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا رَأَيْتُمُ الرَّجُلَ يَتَعَاهَدُ الْمَسْجِدَ فَاشْهَدُوا لَهُ بِالإِيمَانِ فَإِنَّ اللَّهَ تَعَالَى يَقُولُ (إِنَّمَا يَعْمُرُ مَسَاجِدَ اللَّهِ مَنْ آمَنَ بِاللَّهِ وَالْيَوْمِ الآخِرِ وَأَقَامَ الصَّلاَةَ وَآتَى الزَّكَاةَ ) الآيَةَ