The Quran has highlighted this important point in many verses:
“We have sent you as a bearer of glad news and a warner to the whole of mankind, but most people do not know.” (Verse 28 of Surah Saba)
“(Muhammad), tell them, ‘People, I have come to you all as the Messengers of God, to whom the Kingdom of the heavens and the earth belongs.’” (Verse 158 of Surah Al-Aaraf)
The Holy Prophet (PBUH) himself has underlined this point: “I am God’s messenger for all, both those who I live in my lifetime and those who are born after me.”
Moreover, the letters that Prophet Muhammad (PBUH) sent to leaders of different countries are evidence of his universal mission.
One morning, the Holy Prophet (PBUH) called his companions to gather and then he addressed them, telling them to spread the message of Tawheed (monotheism) to the whole world.
He then sent six individuals to Iran, Rome, Abyssinia, Egypt, Yamama, Bahrain and Jordan to convey the message.