What is the wisdom behind the legal permissibility of supplication (du'a)?

The wisdom behind supplication (du'a) is for the servant to turn to their Creator, seeking guidance to what is right, protection from error, and inspiration with strength and knowledge to do good and repel harm. In this lies the realization of servitude to Allah, for supplication is one of the greatest acts of worship and the most important means of drawing near to Him; indeed, it is the foundation and essence of worship, as the Prophet, peace and blessings be upon him, said: "Supplication is worship," and then he recited: "And your Lord said: 'Call upon Me; I will respond to you.'"