Hadith 12 of the book of belief (faith) by Sahih al-Bukhari
(12) To feed (others) is a part of Islam
حَدَّثَنَا عَمْرُو بْنُ خَالِدٍ، قَالَ: حَدَّثَنَا اللَّيْثُ، عَنْ، يَزِيدَ، عَنْ أَبِي الْخَيْرِ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو رَضِيَ اللَّهُ عَنْهُمَا، أَنَّ رَجُلًا سَأَلَا النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ، أَيُّ الْإِسْلَامِ خَيْرٌ؟ قَالَ: "تُطْعِمُ الطَّعَامَ، وَتَقْرَأُ السَّلَامَ عَلَى مَنْ عَرَفْتَ وَمَنْ لَمْ تَعْرِفْ".
Sahih hadith: Narrated 'Abdullah bin 'Amr: A man asked the Prophet , What sort of deeds or (what qualities of) Islam are good? The Prophet replied, 'To feed (the poor) and greet those whom you know and those whom you do not Know (See Hadith No. 27).
Reference: Sahih al-Bukhari 1: Chapter 2, Hadith 12.
Hadith 21 of the book of belief (faith) by Sahih al-Bukhari
(21) Whoever hates to revert to Kufr (atheism or disbelief) as he hates to be thrown in fire, is a part of faith
حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، قَالَ: حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ، قَالَ: "ثَلَاثٌ مَنْ كُنَّ فِيهِ وَجَدَ حَلَاوَةَ الْإِيمَانِ، مَنْ كَانَ اللَّهُ وَرَسُولُهُ أَحَبَّ إِلَيْهِ مِمَّا سِوَاهُمَا، وَمَنْ أَحَبَّ عَبْدًا لَا يُحِبُّهُ إِلَّا لِلَّهِ، وَمَنْ يَكْرَهُ أَنْ يَعُودَ فِي الْكُفْرِ بَعْدَ إِذْ أَنْقَذَهُ اللَّهُ كَمَا يَكْرَهُ أَنْ يُلْقَى فِي النَّارِ".
Sahih hadith: Narrated Anas: The Prophet said, Whoever possesses the following three qualities will taste the sweetness of faith: 1. The one to whom Allah and His Apostle become dearer than anything else. 2. Who loves a person and he loves him only for Allah's sake. 3. Who hates to revert to disbelief (Atheism) after Allah has brought (saved) him out from it, as he hates to be thrown in fire.
Reference: Sahih al-Bukhari 1: Chapter 2, Hadith 21.