This is likely to be a controversial question, so please see the different opinions below.
Answer 1: Means over Message
The military expansion of the Islamic Caliphates in the Middle East, North Africa, and Central Asia was what led to the creation of the merchants and missionaries that arrived in areas not directly conquered by those Caliphates. Then once Islamic beachheads had been established through trade, indigenous Islamic countries would be erected in those areas (East Africa, Indonesia/Malaysia, West Africa, etc.). Within the Islamic Empires, there was incredible pressure to convert to Islam, such as legal inequality between Muslims and Non-Muslims, excessive taxation of Non-Muslims, certain dress requirements for Non-Muslims, etc. resulting in numerous conversions for legal and economic benefits as opposed to honest belief. Of course, we will never know how many people converted because of pressure and how many converted due to the message, but I would be dubious of any claim that held that more converted by message than by means.
Yes Muhammed (SAW)
When he received the message from God, when the people had been very from God.
The Teacher/Teachers of Islam were sent by God(Al-mighty Allah) which were Prophets who spread Allah's message to the human beings & showed them right path to live.
Islam (or rather Moslem citizens and countries) was/were responsible for the building of Baghdad. Everything about Baghdad was influenced by Islamic Principles and Moslem Rulers.
Muhammad became the prophet of Islam after receiving revelations from the angel Gabriel in a cave near Mecca. These revelations were later compiled into the Quran, the holy book of Islam. Through his teachings and leadership, Muhammad spread the message of Islam and gained a following of believers who accepted him as the final prophet of God.
Islam spread over the whole world but with different percentages. More than 50 countries of the world are having Muslim majority population. Refer to question below. If the question is explicitly referring to the Rise of Islam period, Islam expandied primarily along a east-west axis from Spain and Morooco in the west to Pakistan in the east. There was some northward expansion to eastern Turkey and some southward expansion to Somalia.
maybe
this is due to Islam truthfulness, tolerance, and peacefulness. Refer to questions below.
Islam never spread by war. Refer to question below.
The Mongol destruction of Baghdad as a psychological blow from which Islam never recovered; further expansion of Islam halted.
The message of Islam was revealed to him. He was at the age of 40 when it was first revealed to him in the cave of Hira in the year 610 C.E.
In the Middle East.
Islam !!
The main message of Islam to all peoples is that: "there is only one god. He is the Creator, and therefore only he has the right to be worshipped."
The rise of Islam started with the message that was spread by the Prophet Mohammad. After his death the companions who accompanied him through his journey realized the potential danger in losing the message of Islam and the teachings of the Prophet so they set to jot down the revealed knowledge and verses (collectively known as the "Quran"). this move helped preserve the message of islam. during the expansion of the Islamic state the Quran reached many regions of the world, which had slightly different understanding of its contents and thus had different interpretations. this led to the manifestation of different schools of thought and the development of law through their teachings as applied by the rulers of the land.
Message about Faith "non of you will have faith except he wish same as his brother what he wish for himself" in Islam.
The reason why Islam was so successful is because it was spread as soon as the message was given to the prohet Muhammad(PBUH)