We wrestle not against flesh and blood yet we struggle in our flesh. The spirit is indeed willing but the flesh is weak. There are those who has come to God and many are still trying to figure out if what they did at the alta is real. Human nature is where we come from we have come from a sinful state of mind to a unnatural state which should be spiritual. Flesh are the natural thoughts of man thoughts that determine what to do that are good or bad. The reason it is hard for man (meaning) male and female to stay in a spiritual mind or state is fleah our natural minds dictate what we believe and what we don't believe. Therefore, the spiritual state can't stand a chance because we allow our natural to rule more than any other.