Changing from one religion to another is called the same for any of them: conversion.
Tecnically, the religion is called Islam and the people that follow the Islamic religion are called Muslims, so yes, being a Muslim counts as a religion.
There religion was called polyteistic
the person who brang religion in Arabia was no one! Muslims (who believe the religion called Islam) believe that Allah (god) created the religion from the beginning of time which is also written down in their holy book called the quran.
A person who does not in religion is called an Atheist - Atheism
The religion called Shakers.
The priests are called Shamans. They religion is also sometimes referred to as shamanism.
atheists
The person who starts a religion through the commandemnt of God is called a Prophet.
The religion is called Islam; the followers are called muslims; their holy book is the Quran.
Lutherans are Martin Luthers religion.
The religion of Israel, also called Judaism