Islam !!
When he received the message from God, when the people had been very from God.
Muhammad is the founder of the religion known as Islam. According to Muslims (the believers), Muhammad received his revelation from God, and revealed what was later to become the Quran.
Very young compared to judaism and is 600 years younger than christainity, catholicism to be exact. But eastern religion like Hinduism and budhism are even older thousands of years older than Islam.
Islam religion per God Quran revelation to prophet Muhammad is founded by Allah (God in English and same God in Christianity and Judaism) and not prophet Muhammad (peace be upon him). Prophet Muhammad is the God Messenger and prophet who conveyed God message to his followers. Refer to related question below
Muhammad was the prophet of Islam. He is considered the final prophet in Islam, delivering the message of the Quran, which Muslims believe to be the word of God (Allah). He was born in Mecca, in modern-day Saudi Arabia, in the 6th century CE, and his teachings laid the foundation for the religion of Islam.
Answer
Quran & Hadith is message of Prophet Muhammad pbuh .
Many people believe that the religion of Islam was founded by the Prophet Muhammad (peace be upon him) in the land of Arabia. However, Muslims believe that all the prophet's brought the religion and message of Islam and hence there is no single one place where Islam was founded.
Among them are Abraham, Moses, David, Jesus and Muhammad (peace be upon them all). All messengers are prophets who are assigned a message/religion to convey to their people.
The message given by God to prophet Muhammad through the angel Gabriel (Jibril in Arabic) is the holy book Quran. Refer to questions below on Quran.
Well, honey, when Muhammad started preaching his message in Mecca, the ruling Quraysh tribe got their panties in a twist. They were worried that his teachings would threaten their power and influence, so they tried to shut him down. But you know Muhammad, he wasn't one to back down easily.