What is the ruling on one who believes that wearing the galabiya brings him closer to Allah Almighty, and cites the hadith "He [the Prophet] forbade Qaza‘" to prevent people from cutting their hair in certain ways? And is one who refutes their view in the right?

It is forbidden to speak about Allah without knowledge. This includes attributing to the religion something that is not part of it or denying something that is. Wearing a shirt was part of the Prophet's (peace be upon him) guidance; it was his favorite garment, and it is better than other garments, but it is not obligatory. Al-Qaza' is shaving part of the head and leaving part of it, and it is disliked by the majority of jurists. It is not originally forbidden, nor does it include thinning the sides of the hair. The reprehensible extremism and excessive zeal in religion, by forbidding what is lawful and restricting what the Sharia has made wide, alienates people from religiosity. Sincere advice and good admonition must be given to those who fall into this.