This type of question can often invoke a deep-rooted response within us. Here's my attempt at circumventing this by expressing a slightly different question that I believe still answers your question (eventually...)
What was the purpose of religion, back in the pre-civilization era?
Was religion not used primarily as a means of controlling a population - e.g. ancient Egypt?
When I think about the question I posed, I personally don't think "religion" is the root of all evil. I think religion is used as a means of exercising power/control; money is in a similar category (it too is not the root of all evil).
One could argue that wars have been started becuase of religion. E.g., Northern Ireland residents are generally protestant, Southern Ireland generally Catholic - but do you really think that that was the major reason for the conflict in "recent" times? I don't (but I used to!).
Similarly Iraq - was Saddam's war (or Geroges war?) about religion, or religous differences? Some have tried to suggest so.
I used to think that religion was a key factor, and thus a strong contender for the "root of all evil" award, but I think it's guilty merely by association: the real reasons are often shrouded in a religous cloak to hide a more sinister reason for wanting a war: the ability to exercise power and control over a nation/people/region.
So, no, I don't think religion is the root of all evil.
Great question though.