Allah sent Muhammad (S) with the Truth so that he may take out His people from the worship of idols towards His worship and from obeying Satan towards obeying Him and sent him with the Qur'an which He explained and made strong, in order that the people may know their sustainer (Allah) since they were ignorant of Him, may acknowledge Him since they were denying Him, and accept Him since they were refusing (to believe in) Him. 
Because He, the Glorified, revealed Himself to them through His Book without their having seen Him, by means of what He showed them out of His might and made them fear His sway. How He destroyed those whom He wished to destroy through His chastisement and ruined those whom He wished to ruin through His retribution!
Certainly, a time will come upon you after me when nothing will be more concealed than rightfulness, nothing more apparent than wrongfulness and nothing more current than untruth against Allah and His Prophet. For the people of this period nothing will be more valueless than the Qur'an being recited as it ought to be recited, nor anything more valuable than the Qur'an being misplaced from its position. And in the towns nothing will be more hated than virtue, nor anything more acceptable than vice.
The holders of the book will throw it away and its memorisers would forget it. In these days the Qur'an and its people will be exiled and expelled. They will be companions keeping together on one path, but no one will offer them asylum. Consequently at this time the Qur'an and its people will be among the people but not among them, will be with them but not with them, because misguidance cannot accord with guidance even though they may be together. 
The people will have united on division and will therefore have cut away from the community, as though they were the leaders of the Qur'an and not the Qur'an their leader. Nothing of it will be left with them except its name, and they will know nothing save its writing and its words. Before that, they will inflict hardships on the virtuous, naming the latter's truthful views about Allah false allegations, and enforcing for virtues the punishment of the vice.
Those before you passed away because of the lengthening of their desires and the forgetting of their death, till that promised event befell them about which excuses are turned down, repentance is denied and punishment and retribution is inflicted.
O people, he who seeks counsel from Allah secures guidance and he who adopts His word as guide is led 
because Allah's lover feels secure and His opponent feels afraid. It does not behoove one who knows His greatness to assume greatness, but the greatness of those who know His greatness is that they should abase themselves before Him, and the safety for those who know what His power is, lies in submitting to Him. Do not be scared away from the truth like the scaring of the healthy from the scabbed person, or the sound person from the sick.
You should know that you will never know guidance unless you know who has abandoned it, you will never abide by the pledges of the Qur'an unless you know who has broken them, and will never cling to it unless you know who has forsaken it. Seek these things from those who own them because they are the life-spring of knowledge and death of ignorance. They are the people whose commands will disclose to you their (extent of) knowledge, their silence will disclose their (capacity of) speaking and their outer appearance will disclose their inner self. They do not go against religion, and do not differ from one other about it, while it is among them a truthful witness and a silent speaker.
(1) Al-Kulayni, Rawdah, 386;
(2) al-Harrani, Tuhaf, 163.