The definition of the sin

The good is rectitude of judgment or to say the spiritual gift of counsel: listen (perceive with attention), meditate with intuition and inspiration and decide creatively; also it is righteousness of action: the golden rule.
From the definition of the good comes the concept of error, of heresy. Sin is basically a mode to fail.
We can all sin, fail, but when the sin becomes an habit we become sinners, people who fail, people who do not hit the target, who do not aim.
The pursuit of happiness makes us sinners and this is because happiness is an apparent good, only when we seek the true goods, which are eternal life, the fruits of the spirit, the life in common is that when we become people  who live according to the law of God.
http://www.quintoevangelio.com.ar/en/articles/item/110-justice-and-sin.html