The best deed

عَنْ أَبِی ذَرٍّ، أَنَّهُ سَأَلَ نَبِيَّ اللہِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ أَىُّ الْعَمَلِ خَيْرٌ قَالَ‏ إِيمَانٌ بِاللهِ وَجِهَادٌ فِىْ سَبِيْلِ اللهِ عَزَّوَجَلَّ

Hazrat Abu Dharr^ra narrates that he asked the Holy Prophet^sa which deed was best. The Holy Prophet^sa replied, “Belief in Allah and jihad in the cause of Allah, the Mighty and Sublime.”

(Sunan al-Nasai, Kitab al-Jihad, Hadith 3129)