What is the wisdom behind legislating supplication (Du'a) in Islam?

Supplication (Du'a) is a great act of worship that involves seeking refuge and supplicating to Allah. Allah has commanded it and promised to respond. Supplication was legislated because it is an act of worship from which the servant benefits, and it is a means to obtain what is desired and to avert what is disliked. Thus, supplication is one of the greatest means for achieving one's goals.