In the quran, Surah 14:4 And WE NEVER sent a messenger except with the language of his people, that he might make (the message) clear for them. Then Allah sendeth whom He will astray, and guideth whom He will. He is the Mighty, the Wise.

You see that allah swore NEVER to send a prophet who does not speak the language of the people. In Nigeria, English, Hausa, and Yoruba speakers who cannot understand a single dot in Arabic call a man who does not speak their language a prophet even after allah told them that he will never send such a person to them.

Are they being deceived or did they choose to deceive themselves?

Going by your argument even Jesus-Isa (AS) is sent only to the Israelites.

Well, as regarding the verse you are very correct,a messenger/prophet must come From a particular tribe (since there is no singular universal language). But in some instances,it goes beyond.

Having said that, Muhammad (SAW) is sent to not just to his people but the entire mankind, as stated by several verses in Holy Qur'an,as seen below:

"And We have not sent you (O Muhammad) except as a giver of glad tidings and a warner to all mankind, but most men know not.” (Surah Saba’, 34: 28)

Say, [O Muhammad], “O mankind, indeed I am the Messenger of Allah to you all, [from Him] to whom belongs the dominion of the heavens and the earth. There is no deity except Him; He gives life and causes death.” So believe in Allah and His Messenger, the unlettered prophet, who believes in Allah and His words, and follow him that you may be guided"
Quran 7 v 158

So brother,I hope this helps.

Sayman0880:
Going by your argument even Jesus-Isa (AS) is sent only to the Israelites.

Well, as regarding the verse you are very correct,a messenger/prophet must come From a particular tribe (since there is no singular universal language). But in some instances,it goes beyond.

Having said that, Muhammad (SAW) is sent to not just to his people but the entire mankind, as stated by several verses in Holy Qur'an,as seen below:

"And We have not sent you (O Muhammad) except as a giver of glad tidings and a warner to all mankind, but most men know not.” (Surah Saba’, 34: 28)

Say, [O Muhammad], “O mankind, indeed I am the Messenger of Allah to you all, [from Him] to whom belongs the dominion of the heavens and the earth. There is no deity except Him; He gives life and causes death.” So believe in Allah and His Messenger, the unlettered prophet, who believes in Allah and His words, and follow him that you may be guided"
Quran 7 v 158

So brother,I hope this helps.

No, it doesn't help cos the Bible doesn't say that Jesus was sent for the Jews only. John 3:16 God so love THE WORLD. And what did he do? Sent his son.