Tawheed can only be established upon knowledge:

بـسـم الله والحـمـد لله والـصلاة والـسـلام عــلى رسـول الله، وبـعـد

Shaikh al-Islaam, Ibn Taymiyyah رحمه الله reported that Mu`aadh bin Jabal رضي الله عنه said:

“Upon you is to seek knowledge; for seeking it for the sake of Allaah is worship; and understanding it (increases) the Fear (of Allaah);  searching for it is (a type of) Jihaad; teaching it to those who do not know it is a charity; revising it is (like doing) Tasbeeh (Glorification of Allaah);

Through knowledge, Allaah is known and worshiped; and through it He is Glorified and singled out (in worship). Through knowledge Allaah raises the status of the people and makes them leaders and scholars through whom others are guided and are aligned to their opinions.”

[Majmoo` al-Fataawa (10/39)]

In Hilyatul-Awliyaa’ it is also reported from Mu`aadh Ibn Jabal رضي الله عنه with additional wordings:

“Seek knowledge, for learning it for the sake of Allaah is (a sign of) fearing Him. Seeking it is worship; revising it is Glorification of Allaah; searching for it is (a type of) Jihaad; teaching it to those who do not know it is a charity; and giving it to those who deserve it (is a means) of drawing near to Allaah. 

For knowledge sets the milestones for what is Halaal and Haraam; it is an illuminating light to the path of Paradise; a comforter in times of loneliness; a companion in times of seclusion; the one who will speak to you when you are lonely; the one who will guide in times of ease and hardship; a weapon against one’s enemies; a religion with the esteemed.

Allaah تعالى raises (in status) nations by it, making them leaders of goodness, whose guidance and paths are to be followed, those whose actions are looked to and imitated and with whom the final opinion will rests with. Angels prefer to be in their companionship and with their wings they anoint them. Everything in the wet (sea) and dry (land) seeks forgiveness for them, even the fishes in the (deep) sea and the insects; as well as the birds and the animals.

For knowledge revives hearts from the (death of) ignorance; and it is lamp for the eyes in the darkness. Through knowledge one attains the station of the righteous and a lofty status in this world and the hereafter.

Meditating upon it is like (optional) fasting, and learning it is like establishing (night) prayers. Through it bonds of kinship are maintained and Halaal and Haraam are known. It is the leader of actions; and actions follow it. The successful ones are inspired towards (seeking) it and the wretched ones are prevented from it.”

[Hilyatul-Awliyaa’ (1/238)]