You are right..but I'm not sure about the whole Ismeal thing though..I'm not informed about it.
But however, Christianity,Islam and Judaism are three religion that are very close in the matter of beliefs...and I find it quite ironic that so many Christians are bashing Islam..the basis of the three religions are the same. Islam is closer to Judaism then it is to Christianity because Christians believe that Jesus was the son of God which we don't.
The splitting point and the main different about these three religions is quite simple. Muslims, Christians and Jews believed in Moses as a prophet and they believed in his message. Then Jesus came which we Muslim call Isa. The Jews didn't believe in Jesus and rejected his preachings..the muslims didn't exist that point but they believed in Jesus..until people thought he was the son of God. That was when some people have divided themselves out of Christianity. Prophet Muhammed (Peace be upon him) came much much later and both Christians and Jews didn't believe in his message..but however his message was very close as the message that Moses and Jesus have preached.
So pretty much the basis of those three religions are very alike...