'Ilm (knowledge) and 'Amal (practice)

"The one who practices upon his knowledge, Allah Ta’ala will give him a knowledge which he did not have." 

Hazrat Umar Bin Abdul Aziz (Radiyallahu Anhu) said: "It is our negligence of practicing on our knowledge that has made us lack the knowledge of what we do not know. If we had practiced some of what we knew, we would have benefited from such knowledge which our bodies would perhaps not be able to bear." 

Allah Ta’ala said: 

"... Fear Allah. Allah shall teach you ..." (S 2: V 282)

It is a promise from Allah Ta’ala to the one who practices Deen that He will grant him “Nur” in the heart. This Nur will assist him to understand Deen better.

Allah Ta’ala said: 

"O those who believe, if you fear Allah, He will grant you a criterion (standard by which you can differentiate between right and wrong) ..." (S 8: V 29)

Allaamah Al Qurtubi said: 

“When a servant observes Taqwa for his Rabb by following His commandments and by refraining from the prohibitions and he refrains from doubtful things in order not to fall into Haraam, Allah Ta’ala will fill his heart with sincerity and embellish the members of his body with good deeds.” 

[English version of "Ilm (la connaissance) et `amal (la pratique)" – Al Jamiat – Vol.1 No.13]