A man asked the Prophet ﷺ , "What sort of deeds or (what qualities of) Islam are good?" The Prophet ﷺ replied, 'To feed (the poor) and greet those whom you know and those whom you do not Know (See Hadith No. 27).  

أَنَّ رَجُلاً سَأَلَ النَّبِيَّ ﷺ أَىُّ الإِسْلاَمِ خَيْرٌ قَالَ تُطْعِمُ الطَّعَامَ وَتَقْرَأُ السَّلاَمَ عَلَى مَنْ عَرَفْتَ وَمَنْ لَمْ تَعْرِفْ