My father mentioned a quote he heard from Dr. Nader saheb, who was quoting from Imam Ghazaali Rahmatullahi 'Alayh, something to the effect that,
"There are four branches of deen:
Da'wah and Tableegh (calling towards Islam and propagating Islam)
Dars and Tadrees (teaching and learning)
Tasneef and Ta'leef (writing and publication)
Tazkiyatun Nafs (Cleansing of the heart)
They are all laazim and malzoom ie they must co exist. Without Da'wah and Tableegh, the rest of the three are lifeless.
Without the supervision of the rest, Da'wah and Tableegh is fitnah."
The above was said by Dr. Nader saheb with the wagging of a finger, and the adding of "Fitnah hai, fitnah!" ie "Fitnah, it is a fitnah!"