Of all seven deadly sins, envy probably has the worst effects on both the envier and the envied. Often, envy is brought on by another sin. This is the case in the both the stories of Cain and Abel and of Joseph. Envy tears its victim apart and then causes further sins. In both cases, the competition between brothers for a father's favor turns into wrath.
Cain is the older son of two, which would mean that, traditionally, he would naturally have a higher place in his family than Abel. When both brothers must give an offering to God, Cain's selfishness caused him to provide less grand of an offering. Cain chooses a portion of his crops, and Abel offers the fat of his best animals. God looks with favor upon Abel, and this throws Cain into rage. Cain's jealousy turns into wrath and he kills his own brother, in the eyes of his Father in heaven.
Joseph is the youngest of 12 sons, and he is very special to his father, Jacob, because he was born of Jacob's favorite wife. As such, Joseph is treated to nicer clothing than his brothers. After hearing Joseph's dreams of his future place in government, the brothers" envy grows stronger. Their pride is hurt, and they seek revenge. With intent to kill Joseph, the brothers instead sell him into slavery, telling Jacob that Joseph was eaten by an animal. .
The story goes on, and eventually, just like in his dreams, Joseph does have quite a bit of power over his brothers. Years after his brothers" betrayal, Joseph finds himself standing over his own family as they beg for food. They do not recognize him at first, and when they do they must also beg him for mercy. Of course, when Jacob finds that his favored son is alive, he is quite angry with his eleven older sons. Joseph's brothers lose the same pride that contributed so greatly to their envy in order to survive. .
Stories of envy have consistently been written about brothers. In the two biblical stories, brothers turn on brothers when they are not all given equal respect.