Oubliette - We tell them they're in a cult. They deny it and shun us thereby proving our point, yet they fail to see this.
That is what happens in the majority of cases, and since your mother is strong, it is what will happen to you.
If you don't like living a lie, just tell them that you are inactive. Don't say why, no matter how much they push you. It they assume you are just weak, then they can have the hope you jump back in just before Armageddon. If you show them you believe something else, they will classify you as an apostate and view you are dead to them, not just now but eternally.