Galatians 5:19–21, This is how the sin nature lets the world know that it (nature-spirit) exists. What this means is "nature spirit" cannot be seen, heard, touched, tasted, or smelled but we know that it exists through its manifestations, first Corinthians 2:9–12. It is a natural thing for degenerate man to manifest the works of the flesh as described in the above verses, Romans 1:28. The works of the flesh are the result of a reprobate mind that is totally compatible with the sin nature in degenerate mankind. However, mankind has learned to control or disguise the fruit of the sin nature so individuals will be acceptable to each other.