How do you compare unsuitable literature with good?

You should try to take a classic piece, such as Shakespeare or Poe. If it seems horrible compared to that, then it might be unsuitable. Shakespeare and Poe are our foundation of literature.

"Unsuitable" literature can also be something that goes against your religious beliefs. In that case, you will know what it is, because it will make your conscience prick you to tell you that something's not right.

If you're asking about a "compare and contrast" essay, then you make a list of everything that is similar and everything that is different, and talk about each point.