Muhammed was born into the Quraysh tribe in Mecca. I read that when he started preaching it was largely against the use of idols; was he preaching against polytheism or idolatry within the Judeo-Christian tradition?
Not to discourage any further answers but you'll enjoy these older posts:
How did Mohammed know so much about Judaism and Christianity? by /u/shlin28
What was Mohammed's religion before Islam? and What were the religions of pre-Islamic Arabia? by /u/frogbrooks
What was the culture and religion of Arabia like before Islam? by /u/Daeres