The purpose of the opening scene
The purpose of the opening scene in which Cecil's father is shot and killed is to explain Cecil's demeanor, the reason he's so passive and doesn't understand his son's views. Just before his father was shot, he warns Cecil to "never lose your temper with the white man because this is his world". Shortly after, his father is shot, when he attempted to confront the man, who had just raped his wife, proving that what his father had just told him was true. The white man had murdered his father in cold blood, in broad daylight and nothing was done about it. From that point on, Cecil is brought into the house to be raised and taught by racist white people, who undoubtedly continued to instill into him the notion that this is the white man's world. Cecil grows up with this mindset, which is why he was a non confrontational, subservient and docile person and is also why he's able to serve and keep a calm disposition and tolerate the disrespectful conversations and treatment that he sometimes received from the people that he served.
It also explains why Cecil is against his son's actions as a civil rights activist. He remembers what his dad told him right before he is killed..."Don't lose your temper with that man [the white man]. This is his world" and what happened soon after, when his dad tried to confront the white man so he is afraid that his son will meet the same fate.
All typos and misspellings courtesy of a public educational system.