عَنْ أَبِي ذَرٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ قُلْتُ يَا رَسُولَ اللَّهِ أَيُّ الْعَمَلِ أَفْضَلُ قَالَ إِيمَانٌ بِاللَّهِ تَعَالَى وَجِهَادٌ فِي سَبِيلِهِ
It is narrated from Sayyiduna Abu Dharr (may Allah be pleased with him), he says: I said, "O Messenger of Allah! Which deed is the best?" He (peace and blessings be upon him) said: "To have faith in Allah and to strive in His path."