@Gog, eerr..... Mohammed did not invent Islam. He unified and strengthened the religion. Just like Christ Unified a bunch of Jews to strengthen there beliefs in God. Just like Josiah strengthen the Jewish belief.
Both the Christians and the Islams use parts from the Jewish bibles. Both Islam and The Jews Mention Jesus. As a Holy-man / Teacher. It was the same with Muhammad. But and English king basically had the Bible re-writen ( hence Kin James Bible ) And took out the parts connection Christians with Muslims.
But the books of God is not what Post is all about.
Anyhow. So 1st there was Jews. Now, do to the fact that the Jews kept pissing off God and such. The Jews got there arse's kicked alot and kept getting enslaved. Sometime during the time of enslavement. when the Jews was stripped from there land, A bunch of Jews started thinking that they really need to " clean up there act ". So they came up with a bunch of new rules on how to worship and obey God. ( Maybe by Divine insight, maybe just because the way it was going kinda sucked. Thats something that must be asked to God. Anyhoo... ) So, when the Jews broke free from there slavers. THey noticed a bunch of them no longer believed in the old ways. so the Jews got all pissed at the Muslims for not following the old ways. and the Muslims thought that God had thought them the new way to worship him. and so the Jews was living in the past witch was pissing off God. Thus the two Religions was formed.
Now, The Jews still stuck with there old ways. ( I'm going to take a jump here to try and keep this as short as i can. ) So, Now comes Jesus. who aslo see's that the "old" Jewish way was not working out. God was still kinda pissed and the Jews ( hence them being enslaved by the Romans ) And the Jewish high-Archy was kinda corrupted. So Jesus preached yet another "new" way to Worship God. The Jews. Who really thought the old way was the one way to God. Hated Jesus for this. And the Muslims was like " Hey, if you didn't like the Jewish old way, then join us, not form your own way, i mean.. WTF ?! ) Now, to jump to modern times, There is atleast three different Branches of Jews. ( Four if you count Jews for Jesus ), There is Three different Branches of Muslims and there is a shit-ton different branches of Christians. But really, four main Branches.
But they ALL Believe in the same God.
And on a final note. One can find "Pagan" Believes in EVERY SINGLE religion. Be it Jew, Muslim Are Christian. ( and all the other ones that for lack of time / space are not going to be mentioned. Hell, Even Paganism has some forms are Pagan in them. [ IF you don't understand that sentence then you clearly know little about Paganism and thus, shouldn't be commenting about it. ] so, ya, Don't even start with that " he's a pagan " BS.