Losing faith in India will get you nowhere. I will not disagree that our performance against Bangladesh was down right dismal. Remember, India can sometimes do things that we never thought possible. India has broken through a lot of milestones in these last couple of years and the team has it in them. Secondly, whether or not Sri Lanka would want India to go through to the Group of 8 is irrelevant. I don't think that motivates them to do any better or worse against teams. Bottom line is that every team wants to win- all we can do (here of course I am making the assumption that you are Indian which is not based on solid ground but oh well) is cheer our team on and hope for the best. For India!
