Allah said:

﴿فَإِنَّ خَيْرَ الزَّادِ التَّقْوَى﴾

(...but the best provision is At-Taqwa (piety, righteousness).) When Allah required mankind to supply themselves with what sustains them for the journeys of this life, He directed them to the necessary provisions for the Hereafter: Taqwa. Allah said in another Ayah:

﴿وَرِيشًا وَلِبَاسُ التَّقْوَى ذَلِكَ خَيْرٌ﴾

(...and as an adornment; and the raiment of Taqwa, that is better.) (7:26)

Allah mentioned the material covering and then He mentioned the spiritual covering, which includes humbleness, obedience and Taqwa. He also stated that the latter provision is better and more beneficial than the former.

﴿وَاتَّقُونِ يأُوْلِي الأَلْبَـبِ﴾

(So fear Me, O men of understanding!) meaning: `Fear My torment, punishment, and affliction for those who defy Me and do not adhere to My commands, O people of reason and understanding.'

﴿لَيْسَ عَلَيْكُمْ جُنَاحٌ أَن تَبْتَغُواْ فَضْلاً مِّن رَّبِّكُمْ فَإِذَآ أَفَضْتُم مِّنْ عَرَفَـتٍ فَاذْكُرُواْ اللَّهَ عِندَ الْمَشْعَرِ الْحَرَامِ وَاذْكُرُوهُ كَمَا هَدَاكُمْ وَإِن كُنتُمْ مِّن قَبْلِهِ لَمِنَ الضَّآلِّينَ ﴾

(198. There is no sin on you if you seek the bounty of your Lord (during pilgrimage by trading). Then when you leave `Arafat, remember Allah (by glorifying His praises, i.e., prayers and invocations) at the Mash`ar-il-Haram. And remember Him (by invoking Allah for all good) as He has guided you, and verily you were before, of those who were astray).