Select a topic that appeals to you if you have not been given a topic to write about. Choose an issue that is regarded as being from a non-Christian worldview. Narrow your topic enough that you can do research directly about it, instead of a broad topic such as paganism or Islam.
Read about the opposing viewpoint with an open mind. This is necessary to write an apologetics paper that is fair and reasonable and looks at the issue from both sides.
Write down the most basic points of dispute from the angle of the opponent as well as from the Christian faith. Assume that the opposing viewpoint is true, which is the basis of a suppositional approach. Write down any inconsistencies in the opposing viewpoint's argument. Write down how the Christian argument relieves these inconsistencies.
Include an introduction for your paper that outlines the basic argument from both sides. Write a body of the paper that looks at each argument, along with the reasoning from both sides. Finish the paper with a conclusion that summarizes your ultimate argument for the Christian faith. Each paragraph should include three to five sentences, but the overall length of the paper will be determined by your professor.