Answer:
There are many theories which depicts the reasons why did Islam arise. Some says that the main reason was the sword, Islam arose by sword, by conquering different countries of the world but the most widely known and authentic authors say that it is not true. It was the system given by Islam which made it popular and led people entering into it on a very fast pace. It was the unifying power of the Arabic language which made people think about it. These were the administrative rules of Muslims which made it popular. These were the teachings of the Prophet Muhammad (PBUH) which melted the hard hearts of the Arab people. It was the respect which Muslims gave to women, kids, elders and minorities which made it arise.
It was the message of peace for everyone which attracted people towards it. Other religions are not rejected in Islam, Islam says that the main and fundamental message in all religions is same which is the singularity of God.