The traditions that indicate he will return the people to guidance, the Quran, and the sunna
Comprised of many traditions
682. Nahj al-balāgha1: One of his sermons, peace be on him, in which he mentioned the bloody battles:
He will direct desires towards guidance while people will have turned guidance towards desires, and he will turn their views to the direction of the Quran while the people will have turned the Quran to their views. [Before this enjoiner of good, matters will deteriorate] until war will rage among you with full force, showing forth its teeth, with udders full of sweet milk but with sour tip.
Beware! It will be tomorrow and the morrow will come soon with things which you do not know. The man in power, not from this crowd, will take to task all those who were formerly appointed for their ill deeds and the earth will pour forth its internal treasures and fling before him easily her keys. He will show you the just way of behavior and revive the Quran and the sunna which have become lifeless [among people].
The topic of this section has been mentioned in numerous narrations. This is because returning the people to the Book [of Allah] and the Sunna is one of the greatest feats of the Mahdī, peace be on him, and one of his main tasks. One can rarely find a tradition that doesn’t directly or indirectly establish this fact.
Thus, only the person who fulfills this promises can be the Mahdī. He will not rise except to establish the Truth and he will not make the people rise but to return them to the Book of Allah and the Sunna of His Prophet. The world will not be filled with justice and fairness except through him. Allah’s affairs will not be manifested and Islam will not defeat the other religions except by the return of the people to Allah’s Book and the Sunna of His Prophet. Reformative actions will not be accomplished but through him and he will not appear, rise, and emerge except for the establishment of the sharia and for the implementation of the laws of Allah and His religion.