Many people live their lives in a state of sickness.
They roam around absent-mindedly and in neglect, looking for the cure to
their sicknesses, but they do not find it. And they look at one of the
ways towards attaining it so that they can embark on it, but they are not
able to distinguish it! However, the cure is right in front of them. The
remedy is before their very eyes - indeed it is knowledge.
Imaam Adh-Dhahabee (d. 748H) said: "Whoever's heart becomes sick with doubts and false notions, then this condition will not come to an end unless he asks the people of knowledge, so that he learns from the truth that which will repel his sickness. And thus it will not affect him seriously.
The greatest of these cures is: having the (constant) need for Allaah (Al-Iftiqaar) and imploring Him for help (Al-Istighaathah). So let him constantly repeat this (following) supplication and increase in saying it:
'O Allaah. Lord of Jibreel, Mikaa'eel and Israafeel. The One who revealed the Torah and the Injeel. Guide me concerning that which is in dispute from the truth, by Your permission. Verily, You guide whom You will to a Straight Path.' 
And let him constantly renew his repentance and asking of forgiveness. And let him ask Allaah to grant him certainty and well-being. For indeed - if Allaah wills - his days won't come to an end except that he will be relieved - if Allaah wills - from his sickness. And his Tawheed (doing actions only for Allaah) will be made pure for him. And he will be saved from entering into the science of rhetoric ('Ilm-ul-Kalaam) , of which - by Allaah, the Most Great - if it is learned in order to prevent a sickness, there will sprout out from it many more sicknesses, which may possibly even kill him! In fact, no one has a lot of doubts and misconceptions befall him, except he who preoccupies himself with the sciences of Rhetoric (Kalaam) and Logic (Hikmah)!
So the cure for these sicknesses is to throw these destructive matters away and to avoid them completely. And to apply much recitation (of the Qur'aan), prayer, supplication and fear of Allaah to ones self.
So I am guaranteeing for him (by this) that his Tawheed will become pure and that His Lord will grant him well-being.
And if he does not make use of this cure. And the sickness is instead treated by another sickness. And he drowns himself with the remedies of opinions and intellectual choices, then perhaps he may be relieved and perhaps he may be destroyed! And perhaps he may even remain sick until he dies!" 
Abu Ad-Dardaa reported that the Messenger of Allaah said: "Indeed, the scholars are the inheritors of the prophets. And indeed, the prophets do not leave behind deenars nor dirhams as inheritance. Rather they only leave behind knowledge as inheritance. So whosoever takes hold of it (i.e. the knowledge), then he has taken hold of a large share (of the inheritance)." 
Imaam Ibn Hibbaan (d. 354H) said: "In this hadeeth there is a clear proof that the scholars who bear the merit we have mentioned (previously), are the ones who teach the knowledge of the Prophet apart from the many other types of knowledge.
Did you not see him say: 'The scholars are the inheritors of the prophets'? The scholars do not leave anything behind as inheritance, except knowledge. And the knowledge of our Prophet is his Sunnah. So anyone that deprives himself from acquiring knowledge of it, then he is not from the inheritors of the prophets." 
And from the beautiful phrases that have been stated, is:
"Knowledge is the inheritance of the Prophet, such
has been reported In the texts, and the scholars, they are its inheritors
The chosen one
did not leave anything behind other than his hadeeth Among us, so that
is his property and his assets."
1. He is the well
known shaikh of our time and student of Imaam Al-Albaanee, may Allaah preserve
him. This article of Shaikh 'Alee Ibn Hasan is translated from Al-Asaalah
magazine (Rabee' Ath-Thaanee issue no. 1 of 1413H, pg. 50)
2. Something similar to this has been reported by Muslim (no. 770) in marfoo' form. The wording in Arabic is as follows: "Allaahumma, rabba jibreel wa mikaa'eel wa israafeel. Munzil At-Tawraati wal-Injeel. Ihdinee limaakhtulifa feehi min al-haqq bi-idhnik. Innaka tahdee man tashaa ilaa siraatin mustaqeem."
3. This is from the types of philosophy!
Taken From: Al-Manhaj.com