I agree. Without Harry's faith in Dumbledore, Fawkes would never have come and provided him with what he needed to defeat Tom Riddle, Jr. (Voldemort). Ginny's life would have been sacrificed to bring the 16 year old Voldemort to life, and Harry would have fallen to the basalisk.
Harry, more than any other wizard alive has defied Voldemort. Four times (unlike his parents, or Frank and Alice Longbottom). It's also kind of ironic; while Harry places his faith in Dumbledore, Dumbledore has placed his faith in Harry. Harry respects Dumbledore as the greatest wizard in the world, while Dumbledore respects Harry has the only person who can defeat Lord Voldemort.