There is no issue that is more at the heart of the Catholic-Protestant separation than that of Martin Luther and his 95 Theses. Some shy away from it in fear of this confrontation. Others say it is undeniably one of the most important historical moments in history. Regardless of one's stand, most have only read a modern translation or a condensed version which tells the reader what Luther meant by the things he has said.
I have found it best to have my students, once they reach high school, to actually read all of the 95 Theses. Whatever you and your students take from it, and however personal it is, I can almost guarantee that you will get something from reading it. Before you or your student sits down to read them, however, regardless of where you stand on the Catholic-Protestant issue, try to clear your mind of anything you have ever read or heard of about them, because it is important to approach them with a fresh, open mind. This is why I do not spend much time on the issue, only stating the facts that this was a point in history when there was a separation in the Christian church, until my students are old enough to be able to do this assignment. They need to be old enough to read the Theses with as little help as possible, (preferably no help) in understanding what is written. It would be best if it could be read in its original Latin, but we have not been able to learn sufficient Latin in order to do this assignment in Latin. A good translation of the Theses can be found at the Georgetown site. I like it because it is a more direct translation than most, which try to clean up his writing. For example, it has his original numbering and it has Luther's repetition of "again" as his theses 82-85 (translation numbering), which often gets cut in translations (example of this can be found here.)
The assignment is quite simple really. As your student goes through the readings (more than one reading is preferable) have him make notes on what Luther is saying, writing down these in the student's own words. Have your student make a notation on where the concept he is noting is stated in Luther's text. If Luther says the same concept more than once, have your student write down where the concept is written each time it is stated. Although simple, this assignment is difficult and so you will need to give your student as much time as he needs to do this thoroughly, or it is not worth doing at all. Other aspects that could be explored include seeing if your student can draw from Luther's word choices what he was feeling as he was writing them? What was his emotional state? Why do you think this?
It is a good idea for you, as their teacher, to do this assignment yourself before you give the assignment to your student so that you can have a better understanding of how difficult it is to accomplish. Besides, I believe that it is an important thing to do for everyone as this topic is mentioned so much and talked about so much, but few have actually read them thoroughly, preferring to take another's assessment of them. (By the way, I also do a similar assignment with regards to Charles Darwin's works, but that is another post...)
My son Sam found getting through the assignment too tedious to complete, (he does have ADHD) but by the time he had finished, had had gain enough insight for the assignment to accomplish its goals, so we stopped. I encourage you to assess this yourself as you know your student better than anyone else.