Disadvantages of limiting oneself only to books
Question

                What is the way to gain knowledge? What are the obstacles faced by the seeker of knowledge?
Praise be to Allah. 
          There are two ways of acquiring knowledge: 
 
          1 – Acquiring it from trustworthy books, 
          which have been written by scholars who are known for their knowledge 
          and trustworthiness and whose ‘aqeedah (belief) is known to be free 
          of innovations (bid’ah) and myths. 
 
          Taking knowledge from books can help 
          a person to reach a certain level, but there are two obstacles: 
 
          The first obstacle is that this takes 
          a long time, because one needs a lot of time and a lot of painstaking 
          effort until he gets the knowledge he wants. Many people may not be 
          able to overcome this obstacle, especially when they see that those 
          around them have wasted their time without gaining anything, so they 
          get bored and tired, then they do not get what they want. 
 
          The second obstacle is that the knowledge 
          of the person who acquires knowledge from books is usually weak, because 
          it is not built on a solid foundation. Hence we find many mistakes made 
          by those who take their knowledge from books, because they have no guidelines 
          or principles with which to deal with minor issues referred to in the 
          Qur’aan and Sunnah. We find some people come across a hadeeth which 
          is not mentioned in the reliable books of Saheeh and Musnad, and this 
          method goes against the principles followed by the scholars and indeed 
          by the ummah, then they take this hadeeth and build their belief on 
          it. Undoubtedly this is wrong, because the Qur’aan and Sunnah have principles 
          around which the minor issues revolve, and if there is something that 
          contradicts these principles and cannot be reconciled with them, then 
          that should be abandoned.  
 
          2 – One of the ways of gaining knowledge is to learn 
          from a scholar who is trustworthy with regard to his knowledge and his 
          religious commitment. This way is quicker and is more reliable, because 
          in the first method the seeker of knowledge may go astray without realizing 
          it, either because of misunderstanding or because he is lacking in knowledge, 
          or for some other reason. But in the second method he can discuss, give 
          and take with his teacher, which will open to the student many doors 
          to understanding and examining, how to defend the correct views and 
          refute weak views.  The student should prioritize and read book 
          which summarize knowledge before studying it in depth. In this manner 
          he will progress gradually. He should not move on to the next level 
          before he has thoroughly grasped the current level; in this way his 
          progress will be sound.