Please treat me as if I am a native that's been living all my life in the deep jungles of the Congo. Tell me the so-called proof or evidence so that you can convert me.
It is an interesting question, and unfortunately I don't have valid proof.
But my answer to the question, (say if I just had to convince them to save my life,) is that I would invoke fear of the unknown as proof. I would cite thunder and lightning and sickness and insect swarms as an upset God. They'd better toe the line if they want to stay alive and well.
I'm guessing this is where the need for religion stems - fear of the unknown.