Islam is a Pagan religion. One of many practiced by the tribe of Qureysh of whom Muhammad was a member.
Muslims and Christians do not pray to the same God.
The star and crescent moon is the flag of the tribe of Qureysh of whom Muhammad was a member.
Every Arabic tribe had its own flag and symbol and they all worshipped several deities.
Allah is not the word for God but is one of the Gods that the tribe of Qureysh worshipped.
When Muhammed through murder and war united the Arabic tribes they were forced to accept the religion that Muhammed had created.
The criteria for the office of a prophet in the bible is that if a prophet tells you anything that does not come to pass then you are to stop listening to that prophet.
Muhammed predicted a victory in a battle and his followers were severely defeated and Muhammed suffered a bad injury.
Muhammed was not a prophet of God but was the mastermind of his own religion which he used force to install.