Apparently you've missed much of the news over the past 1,400 years, but even within your lifetime, the slaughter of infidels by various Islamic factions has been a more-or-less daily news item since at least the 1980's.

Read the Koran.  There are passages that may be ignored by Muslims in the west about as broadly as the Bible is ignored by Christians, but the murderous edicts and the blessing of deceit are encoded within.  And yes, it is about interpretation, but how much comfort is there in relying on 'most'?