Or not go at all. They dont expect all the people they invite to go. And if you're not comfortable with bible study, it's ok to say no.
How you choose to handle it is an entirely different matter. You could, for example, merely avoid going and hope that nobody takes notice of it and contacts you. Depending on any bonds you may have, that may well be more easily said than done. You could politely explain your reasons for not going. I'm partial to that approach, as it is honest, it isn't something they can argue about without proving themselves to be pushy fanatics, and isn't something you need to continually supply excuses for. Of course, telling an outright lie is always an option, but at some point, after being lied to so many times, they'll catch on. And that will serve to the detriment of any relationships you may want to form with individual members outside the context of the group.