At the very core of Islam there are the concepts of martyrdom and jihad. In Sunni Islam many view Jihad as the sixth pillar of Islam (although unofficially). In Twelver Shia Islam, Jihad is explicitly defined as one of ten ancillaries of the faith.
Most people are familiar with the concept of "lesser jihad" i.e. the physical "holy war" against the enemies of Islam. Other problems include followers’ believing that the Quran is the verbatim word of God and combined with the hadiths there are numerous abhorrent explicit references to how homosexuals and Jews are to be systematically slaughtered.
Many liberals who perpetuate the argument that Islamist conflicts/jihads are geo-political causes (Mehdi Hasan) and not the result (or to some degree) of religious inspiration are blindly ignorant to the unequivocal facts. Continually two arguments (that are 100% true) are offered to deflect criticism of Islam:
Terrorism - the numbers game; "It's a small minority committing acts of terror" - Islam has 1.5 billion followers, a minority of this could still be a significant number-how many of the majority support the actions of the minority without taking up arms?
The Quran/hadiths and preachers/scholars - Numerous abhorrent statements and sound bites (I won't list them - just do some research particularly into the hadiths). A "small minority" of preachers/scholars justify the murder of apostates, encourage militant jihad, promote "dhimmi" status for non-believers, murder of homosexuals, sharia law and genocide of the Jews as explicitly stated in the hadith. How large and influential is this small minority?
Journalists who display great intolerance by playing the "Islamophobia" and "numbers game" card are stifling any debate or criticism of a major world religion. All religions should be open to the same level of scrutiny as for example politics, but for some reason (mainly due to fear of offence or reprisals) religion is insulated from the awkward questions that it has a duty to answer. They force us to play a game of Muslim Roulette since we can’t tell which Muslim is going to blow himself up until he does. And their indifference about the evil being committed in the name of their religion is a big reason why their reputation is where it is.
So while I understand that most Muslims are not at war with us, they’ve proven in their silence and inaction against jihad that they’re not on our side either, and there’s nothing we can say or do to change that.
Another problem with Muslims who aren’t very Muslim is that they lead some among us to conclude that they must be practicing a more enlightened form of Islam. They’re not. They’re “practicing” life in non-Muslim countries, where they are free to live as they choose. But their “Islam” is not the Islam. There’s no separate ideology apart from Islam that’s being practiced by these Muslims in name only, there’s no such thing as “Western Islam”.