Suppose we pour a measure of salt into a container of pure water. The salt affects every drop of the water to the extent that all the formerly pure water becomes salty. From that time on, every bit of water drawn from that container is salty and no pure water can be drawn. This is similar to the depraved condition of man. The first sin was an act, one act that brought sin into the human race. Since that one act the very bloodstream of the human race has been polluted.