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The natural man is the one who goes as far as the human sense permits, which is a limitation. He only functions in the realm of the tangible. He is limited to the sense world, yet there is an invisible world that creates the visible.This realm is called the spirit realm; it's invisible to the human sight and sense, yet its a store-world, where every existing thing comes from. The natural man is the one who does not have the God kind of life, he is a man of flesh and blood only!