They were all true and righteous. Now God sent the Prophet Muhammad with the same message, but in the broadest, the most complete and the most perfect form so that it could meet the needs of all humanity for all time. For example, it was revealed to the Prophet Muhammad, for the first time ever in human history, that Allah is Lord of all the worlds . This statement is placed at the beginning of the Holy Quran. Allah treats all nations, peoples and races equally, cares for their physical and spiritual welfare equally, and does not favour or disfavour any nations unjustly.
All human beings have the highest potential.
It is their use or neglect of that potential which makes them superior or inferior. He sent the Prophet Muhammad for all the world with an all-comprehensive message. And He named it Islam to show that its teachings are not named after, nor attributable to, any individual or to any nation or to any geographic land. But rather this name tells us the principle of the religion. The Quran also teaches us that true religion does not consist of doctrines artificially forced on man, but rather it is in harmony with the inner nature of man.