Islam and by the arabs
To be entirely fair, it was Türkic Tribes of Central Asia who spread Islam to China, but the reason that Arabs spread Islam to Spain, Sicily, and India was that they genuinely believed it to be the correct religion.
the muslims
The Islamic Conquests spread Islam throughout all of the Middle East,North Africa,and Spain.
The Arabs brought the Muslim religion (Islam) to Africa.
The Arabs and Muslim have contributed immensely to the spread of Islam by spreading it to other continents such as Africa. A Muslim is a practitioner of Islam, so if Muslims did not exist, Islam would no longer be practiced (just like the Ancient Greek Religion with Zeus is no longer practiced). The Arabs were the first Muslims and were responsible for spreading Islam throughout North Africa and the Middle East.
The Arabs spread Islam by conquering the people around them. Then they put high taxes on non-muslims. They beheaded a number of people worshipping idols. So, they used a mixture of techniques.
Muslim Arabs from Egypt spread into North Sudan and brought their Islamic faith.
The nomadic people in Arabia who were pastoralists and had much to do with the Rise of Islam were the BEDOUIN ARABS.
The Arabs are a primarily ethnic group that historically inhabited the Arabian Peninsula. Islam, on the other hand, is a religion that originated in Arabia and was founded by the Prophet Muhammad. While many Arabs are Muslim, not all Arabs are Muslims and not all Muslims are Arab. However, Islam has had a significant influence on Arab culture, language, and history, as the religion spread throughout the Arabian Peninsula and beyond.
Islam.
Many factors contributed in the spread of Islam in Africa. The kind, compassionate and based on equality and justice treatment of the Muslimforces and traders impressed the African people and they embraced Islam.