Do we have to Hadith narrations

[Sardar Miyan]

Though Arabs did not write any
thing during and immediately after prophet demise but the
Ajami ( Irani) Muslim had taken
up this job by collecting the events of Prophet Mohammad
from different people who were
not alive then but know some
thing from their elders thereby
brought out some stories link
to Prophet. This is called Hadis
which is called secondary source while Quran is called
original source. Most of Muslims do not believe in these
stories as these were written by
some author.
Now in most of the Masajid in
all over the world the Khateeb
narrate Hadith alongwith Quran.
I do not know as to why they
narrate the Hadith when Ayaat
of Quran are there? They also
narrate Duas that the Prophet
asked which are not in Quran?
In short is right to do so ?