It seems to me that if they want a social visit they should invite you to their home - they're the ones that want it, so they should be the ones to have to go to the trouble of preparing the home for guests, handling entertainment, etc. It's not a purely social visit - if it were then mr elder would be fine with hosting - it's because he's doing this as a part of his duties that he's looking for a way to reduce the load on himself by inviting himself to your house.
My own personal thought is, instead of hosting them at your home at their request (very odd indeed), I would willingly accept their invitation to connect on a social basis but do so at a neutral location like a restaurant.
I'd respond to them, lettting them know you're looking forward to getting together, but it's too hectic at your place. To "keep it simple" let's just meet at Restaurant Bar & Grill for a nice dinner (and drinks, of course). It will set a reasonable time limit on the conversation, and meeting in a public place will force them to tone down the "cult speak" and any temptation to start asking you personal questions on your spirituality, etc.