Too many Westerners are idiotically polite in stating that the terrorists are mutilating and misinterpreting Islam. Such is not the case. In fact, the biggest difference between Muslim terrorists and the rest of the Muslims is that the terrorists are a bit impatient. They want sharia to be implemented in their relevant geographic location and soon everywhere. The non-terroristic Muslims are patiently waiting for the West to crumble and then, with strength in numbers, sharia will be enforced on Western soil.
The ideology is the same. Only the tactics differ.