I recently heard an interview w/Robt Sopenser who correctly identified islam as a political movement (like communism) but uses the false image of religion to protect itself.
My understanding, in part from reading the koran itself, is that it is a blueprint for a complete society including personal, governmental, judicial, religious and societal elements.
It is also not at all voluntary. A muslim must accept all parts of islam or face severe punishments under their sharia code of justice. This includes getting every person in the world to covert to islam, become a tribute-paying slave to islam, or killing those who won't do either. This jihad is mandatory.
Islam is the opposite of our Constitutional Republic and the personal rights and freedoms we enjoy. Islam cannot exist in the United States at the same time as our own Constitution. This is why we must literally fight the war that they have started or we literally lose our very civilization.