In the Quran, Allah exhorts us to make du'a or supplicate to Him, saying, "Call upon Me; I will answer your prayer" (40:60).  Yet it seems that we do not always receive what we ask for in our supplications.  How do we reconcile this?  What is du'a really for, and how should it be made?  In this session, we glean answers to these and other questions, and learn the relationship between du'a and worship in general, via readings from the Twenty-Third Word of the Risale-i Nur.