What can be done to draw closer to God so that He may heal a 5-year-old son who does not speak, and so that he may begin to speak?

A Muslim must be content with and submit to Allah's divine decree and destiny, for this is a part of perfect faith. Allah Almighty says: "And it is not for a believing man or a believing woman, when Allah and His Messenger have decided a matter, that they should [thereafter] have any choice about their affair."

A believer is obligated to employ useful means to treat any affliction or calamity that befalls them. Among these means are: 1. Supplication (Du'a). 2. Acts of obedience that draw one closer to Allah Almighty. 3. Lawful medical treatment; for Allah Almighty has not sent down a disease without sending down a cure for it, except old age.

Therefore, you must submit to what Allah has decreed, while utilizing all possible beneficial means to treat or alleviate the matter by consulting specialized doctors.