The Importance of Acting Upon Knowledge
“The Lord of Honor would reveal the Quraan one, two, or three verses at a time and would require them to act upon those verses. The Companions of the Messenger of Allaah would take one, two, or three verses – never more than ten at a time – and then go act on them. They would then come back, learn some more, and go act on what they learned. As Ibn Mas’ood said, “We learned knowledge and action with the Quraan.”
Therefore, it is very dangerous for you to have a lot of knowledge while having only a modest level of action. The one who hears you thinks to himself “MaashaaAllaah!” He hears you talking about this verse from the Quraan, this hadeeth, the hadeeth being authentic, the hadeeth being weak, ‘aqeedah, Islamic history, the khulafaa’, ‘Umar said this, Abu Bakr said that – may Allaah be pleased with them all. However, you are ten centimeters when it comes to action, and when it comes to knowledge you are over three meters. There is no balance! This is a disease.
Having a lot of knowledge without action is a disease just like having a lot of action without knowledge.”
[At-Tarbiyyah Al-Jihaadiyyah Wal-Bina, by Shaykh ‘Abdullaah ‘Azzaam, 3/182-183]