Religion was the excuse for the inquisition, divine right colonization, forced conversions, witch hunts, ritualistic sacrifice, crusades, Islamic terrorism, etc.
So you're saying that Muslim terrorists are not religiously motivated and instead hijack the religion and use it as an excuse?
In the case of Islam though - considering Sharia law and how Islam brutally and mercilessly grabs power - I would venture that political power was Muhammed's goal from the beginning and that the "religion" was fabricated for that purpose, i.e. Ummah.