grammar in arabic is the keys  to know the charm of arabic language ... 
in grammar you will know about words and sentences , 
generally every word in arabic has what we call the 'root' 
the root is composed of 3 lettre , written like that (a , b , c ) ===   (ف , ع , ل ) 
from this root , we extract verb and nouns and adverbs .. etc 

for exemple the verb  to eat : أكل  (a ka la )  : the root is (أ , ك , ل)   

why the root is important : to distingue origin arabic word from foreign word , so we can keep the language stable and safe from any changement , it is important  to keep the language alive so it never disapear or change 

Yes! Even I am Islam and I read Al-Quran then last semester I joined Arabic class, but it's still difficult!

:D