Death is represented differently in the three literary works that we covered this term (Macbeth by William Shakespeare, "The Sniper" by Liam O’Flaherty, and "The Lottery" by Shirley Jackson). How is it represented in each and why is it important? Please respond in a five-paragraph essay, using specific evidence from the literary works.

Like the writing prompt indicates, each of the three stories does contain death. The presentation of the deaths does differ in each story, as does the body count. Macbeth sees eight total deaths through the events of the play, and "The Lottery" only sees a single death. "The Sniper" has a total of three deaths. The deaths are similar in that they are all intentional. Tessie Hutchinson is stoned to death by the crowd in order to fulfill the tradition. Several of the deaths in Macbeth are caused through combat, and that is how "The Sniper" has the deaths occur. The other deaths in Shakespeare's play are murders, and you could probably make a case that Tessie's death is also a form of murder.
If I'm honest, a five-paragraph essay seems to be an overly short requirement to adequately compare and contrast these three works. If that is a hard and fast requirement, my recommendation is to have an introductory paragraph, a conclusion paragraph, and three body paragraphs. Each body paragraph will discuss each of the literary works mentioned in the prompt. Having only five paragraphs does not give a lot of room to compare and contrast, so I would decide whether or not to convince your reader that the deaths are similarly represented in each story or quite different from each other.
Regardless of the chosen writing angle, you have to craft a thesis that guides the following arguments contained in those paragraphs. All three works definitely have a theme of death, life, and/or mortality. I think all three works also show how death and killing might trigger guilt and remorse as well. Lady Macbeth's increasing guilt and mental deterioration are a major part of the play and result directly from her involvement with the murders. I believe that it also has to be said that the sniper is probably met with crushing guilt at the end of the story when he finds out that he has killed his own brother. "The Lottery" does have the guilt angle in it, but it isn't as overt. There is a moment about halfway through the story when Mr. Adams questions whether or not the lottery should continue. I think an argument could be made that he has some resulting guilt from his participation in previous lotteries. What has to be noted is that he is one of the first to begin throwing stones at Tessie. His guilt and/or fear of the lottery is gone now that he knows he isn't going to be the one that dies.
I believe that for the purpose of your essay, it is better to show your reader how the stories are similar. Have your thesis steer the paper toward making an argument about how all three works are similar thematically. Normally, I would recommend a thesis that starts with "although."
"Although the three works appear quite different from each other, they all thematically deal with death and its repercussions."
I don't recommend that particular thesis based on the five-paragraph limit. That thesis format would almost certainly require a sixth paragraph that explains to readers how the stories are different from each other. Therefore, the thesis should be something more like the following thesis.
"The three stories are all thematically similar in that they all show death and related repercussions."