The first being, "What is sin?" Without an objective standard, it causes a lot of confusion and division.
The second being, "Why do we sin?" Not the easy sins - like lying to protect our image, or things we can never get caught for that benefit us.
Big sins, stupid sins.
Like, say, Eliott Spitzer.
The story is only tenuously connected to Spitzer, especially with a comment like:
"when people operate above or below a certain level of moral self-worth, they instinctively push back in the opposite direction to reach an internally regulated set point of goodness"Yea, I've spent my whole life prosecuting bad people, so I'll balance it out by engaging in some prostitution.
This story flows a lot better when you think about it in terms of sin.
Man inherently understands sin (although he may consciously reject it). This understanding drives justice.
Man is also self-righteous (believing himself more good than he really is), and works-righteous (doing good to cancel out bad he has down).
This is achieved largely through justification (man is self-justified, that is, made right in his own eyes; according to his own standards).
A man like Spitzer would say, "I have worked hard, I deserve this". Or "It is only a small thing, I can stop any time". Of course, he is enslaved to sin (Romans 6:17).
That is the overwhelming sinfulness of sin.