I believe Ben is telling the truth. He keeps saying that we are the good guys, and you(losties) are the bad guys. I think the writers are telling us to take him at his word. Our losties have all done something wrong in their lives as seen by there flashbacks. I believe that is why the show is told in flashback, to show the sins and and connect the characters, to bring them all to Austrailia and in turn to the island. In staying with one of the themes of the show they are all sinners in some way. Why in real life would we trust any of them. I believe that they are on the island to either, A: be punished for these mistakes or B: in some way make amends. We still don't know much about the Others and the reasons for doing what they do. If the Others are the "good guys" it doesn't bother me at all. Some of the most interesting and sympathetic heros of all time, in movies, tv, and books have been anti-heros. I for one believe Ben.