Who could be more conscious than Muhammad(peace be upon him) of the universal nature of the teachings of Islam and the responsibilities that fell on the Prophet for spreading its message in the whole world.
The God of Islam is Rass al’-Aalmin, the Lord of the universe: He is the Rabb al-nas, Malik al-nas, Ilah al-nas-, the Lord, the King and God of men: not only of Muslim, Jews or Christians, alone but the Lord of all the creation ; the Creator and Sustainer of all man kind, and not a tribal deity who is pre-occupied with the destinies of one particular tribe or nation, adjusting all the people to the requirements of a chosen few.
Just as God is the Lord of the whole universe, similarly His last Prophet(peace be upon him) is the Mercy for all the worlds:
We have not sent thee save as a mercy to all the created beings.
So is the case with the religion that has preached. Its message is universal and transcends all barriers of caste and color and those created by geography:
Blessed is He who hath sent down al-Furqan upon His servant, that he maybe a warner unto all created beings.