Why are people so narrowminded to think the religion of Islam leads to Terrorism?

Im white, English and not religious. However, I am sick to death of American Christians persecuting the Islamic faith because of a handful of extremists who believe in that same religion. The amount of racial abuse you read from narrow minded individuals and groups who have no idea of the world around them is incredible! How can people make such judgments. Every country has in its past commited attrocities, but not religions! Should we hate Christians because of what adolf Hitler did?