In those Iron Age days when people asked questions like, "where did good and bad come from", instead of thinking about it rationally they came up with weird stories to account for things they couldn't understand. Hence, daft stories about magic gardens, the tree of knowledge and talking serpents.
The one thing that stories like this require is that you suspend all disbelief and simply accept. I would imagine that in most devout Christians minds the very idea of asking questions like this is to question God's plan itself and is therefore a sin and so they conveniently shut off that part of their brain and stick with what they have been trained to think and say. This is why using logic and reason to debate people like this never works!
The one thing that stories like this require is that you suspend all disbelief and simply accept. I would imagine that in most devout Christians minds the very idea of asking questions like this is to question God's plan itself and is therefore a sin and so they conveniently shut off that part of their brain and stick with what they have been trained to think and say. This is why using logic and reason to debate people like this never works!