Oh no! Now you've got me worried! Then, perhaps, I might ask why they believe in hell. I might suggest that it might be preferred to the hell being made on earth. Or, perhaps, you've already brought me there.
I make up some nonsense about the FSM and what it is going to do to them for not doing it. I love it when they claim I am being stupid suggesting such things as I can point out to them that it is exactly how their nonsense sounds to everyone else.
I basically ignore them. I don't believe in either a heaven or a hell. If someone insists on pushing it in my face, I tell them what Lucidmoon does, that if there is a hell, I'll have a lot of good company.