Parshas Noach begins with a description of the decadent and corrupt society that was ultimately destroyed by the flood. The sins of theft, and illicit relations, are singled out as the primary cause of the world's destruction. It is not coincidental that these two transgressions were simultaneously prevalent in society at the time. The underlying cause of each of these sins is identical.
The sin of theft stems from a basic flaw in our relationships with one another. Individuals can be giving, seeking out opportunities to perform acts of chessed; conversely, one can be become dependant on others, seeking out opportunities to take. Those who are accustomed to taking, may eventually become the ultimate takers, "thieves", whose need to take knows no bounds. The ultimate protection against sinking to the level of actual robbery is to perfect the attribute of "giving" as opposed to "taking".
The family setting provides the perfect opportunity to become a giving person. Marriage can only flourish if both partners constantly give to one another. Raising children is a lifetime opportunity to give. One who only takes cannot fathom the prospect of marriage and child-rearing.
Sometimes healthy, loving relationships of giving between husband and wife, are abandoned and self-centered acts of passion are performed. Rather than bringing children into the world, abominable acts are propagated for the sake of personal pleasure.
The generation of Noach had sunk to the depths of immorality and corruption. The source of all evil engulfing the society in which Noach found himself was the inability to give to others. One who takes, but does not give becomes so self-centered that the needs of others are completely excluded. The sins of theft and moral depravity are the eventual outgrowth of such a character flaw.
Hashem singles Noach out to survive the flood and begin civilization again. The most critical lesson Noach and his children must impart to all future generations is the significance of giving to others.
To reinforce this lesson among Noach and his family, Hashemdevised a plan in which the animal world would be saved. Noach and his family members would be responsible for caring for all of the animals in the teivah for almost an entire year. Hashem could have saved the animals through many means, yet this method was chosen in order to grant Noach the opportunity to perfect the trait of giving, preparing him to instill this most critical trait in his descendants.
The story of Noach ends on a tragic note. After Noach became drunk, his son Cham committed a terrible sin. There are two opinions in Chazal as to Cham's exact actions. According to one opinion, Cham had relations with his father; according to another he maimed his father so that he could no longer have children. Both interpretations indicate that Cham had not learned the lesson of giving. Whether he was involved in an immoral physical relationship reminiscent of pre-delugian society or whether he prevented his father from bringing more children into the world, Cham had sunk to the depths of sin which emanate from a lack of giving.
The lesson of giving would be transmitted through the descendants of Shem, and ultimately be exemplified in the personality of the "the man of giving", Avraham Avinu.