Some non Ahmadis say prophets do not bring shariahs or laws, while messengers do. This ideology is totally baseless. Holy Prophet(saw) never said this. The truth is Quran and hadith show that these two words are directly related. Both words are used for Holy Prophet(saw) and for Hadhrat Isa(as).And In surah Al Maryam in the same surah Moses(As) is called rasool and Nabi who we know brought a shariah, same surah three verses after Hadhrat Ismail(as) is called a rasool and Nabi when we we all know he did not bring a shariah.
They made this misunderstanding that its two different types of people sent by Allah. Allah sends the message to the rasul and than he spreads it to people. The rasul is the one who receives the message from Allah and when he spreads it, he is indeed a nabi. The purpose of a nabi is to spread the message that Allah sent him as a rasul. Never would Allah choose a rasul who would be too scared to spread the message, therefore all messengers are indeed prophets.
A prophet who is sent the message is a rasul. When he spreads the message that Allah revealed to him and tells people this message he is a nabi. When One person but two words for the same person. No difference at all.
The word nabi, comes from the world nabah. The Nabi spreads this message from Allah to the people of where he is sent. Every prophet gets the message of Allah as a rasul and he spreads it which makes him a nabi. Its basically us and breathing Allah sends us to this world and than we breathe to live, A rasul is sent a message from Allah, spreading this message is his breathing as a nabi he is telling people this message. No prophet was ever sent that did not deliver the message.
Here is Quranic proof that they are the same. We have a law bearing prophet called a Nabi and rasul and also a non law bearing prophet also called a nabi and a rasul.