Kate - please describe how faith / religion investigates truth? My opening statement should inform you that I accept that religion can co-exist with a scientific viewpoint.
Inspiration to perform scientific study is great. Scientific study is not religious - it is a methodology - though it can study the religious (and the atheist for that matter). It involves no prayer nor worship and invokes no deity.
Dawkins certainly seems driven to explain himself over and over again because so many ill informed and faith based thinkers continually try and denigrate the knowledge that is staring them in the face. Sometimes the religios need to shut up and admit they haven't done the research necessary to discuss the topics but at every debate you'll always have some zealot thinking or asking some astonishingly poor questions born of bible / dogma based information (written thousands of years ago by uneducated people!) rather than listening to an expert in the field.
I cannot think of one useful scientific discovery given by the gods of the believers (loads of rules for controlling sex,eating food and giving money to priests though).