How to make a burning bush?
As a long time, former Props Master, and given that this is a Church production, regarding what you consider a sacred event, I suggest if anyone is paying attention to the context of the burning bush, they are missing the point. I do have a suggestion however. NO live flame, gee. The fan and fabric idea might work, and shops such as Spensers Gifts sell fake flame torches, etc., but you could use an actual bush, OR some craft item branch that has many small branches, and string it with the lights one uses at Christmas time. Obviously flashing or twinkling in sequence would help the effect, as well as Red, White, Yellow, Orange, even some Blue bulbs anpatterneded to look like the real essence of a fire. I’ll assume the scene won’t be in bright stage light anyway, and you could use colored tape to hide white or green wiring, OR the paper type green Florists tape, wrapped.