Dante Alighieri's The Divine Comedy is considered one of the greatest literary works in the world, and Christianity owes much to his work. Even though it is called a "Comedy", if you read it today it probably wouldn't be that funny, but comedy had a different meaning in the Renaissance. "Tragedy" and "Comedy" had to do with classes; Tragedies were more sophisticated and aimed at the higher classes in society, while Comedies were simpler reads that anyone off the street could enjoy. The Divine Comedy is about a journey through Hell, meeting the Devil and coming out the other side to Purgatory and Paradise. What Christianity owes to this work is that before it, there had never been quite a description of Hell. People would read it, get scared, and run to the Church for protection, because the poem is very graphic.
For more information on Dante and The Divine Comedy, click here.