Narrated Anas bin Malik: Allah's Apostle (saws)mentioned the greatest sins or he was asked about the greatest sins. He said, "To join partners in worship with Allah; to kill a soul which Allah has forbidden to kill; and to be undutiful or unkind to one's parents." The Prophet added, "Shall I inform you of the biggest of the great sins? That is the forged statement or the false witness." Shu'ba (the sub-narrator) states that most probably the Prophet said, "the false witness."
Narrated Abu Sufyan: That Heraclius sent for him and said, "What did he, i.e. the Prophet(saws) order you?" I replied, "He orders us to offer prayers; to give alms; to be chaste; and to keep good relations with our relatives.
Dua for the day
ربَّنَا اغْفِرْ لَنَا ذُنُوبَنَا وَإِسْرَافَنَا فِي أَمْرِنَا وَثَبِّتْ أَقْدَامَنَا وانصُرْنَا عَلَى الْقَوْمِ الْكَافِرِينَِ
Our Lord! Forgive us our sins and anything We may have done that transgressed our duty: Establish our feet firmly, and help us against those that resist Faith.. ameen