You have created a stellar thematic statement and thesis regarding power, corruption, and core values. A thesis statement, of course, is the main point of your essay that will be both explained and proved. To answer your question, yes, it will be quite easy to “argue” your point. Allow me to suggest a few ideas that might serve as body paragraphs for you as well as the specific supports involved.
Two or three of your body paragraphs could be about how Liesel’s book thievery is the main way she resists the Nazi regime and stays true to her core values. Each book in the list can be mentioned as a separate piece of resistance by Liesel. The books Liesel "steals" are as follows: The Grave Digger's Handbook, Faust the Dog, The Lighthouse, The Shoulder Shrug, Mein Kampf, The Whistler, The Dream Carrier, Song in the Dark, and The Complete Dulden Dictionary and Thesaurus. Perhaps you could organize the books on the list into paragraphs by who helps Liesel and why. For example, Rudy helps her steal quite a few. Other books are given to Liesel as gifts (and are not really stolen at all). Others are acquired with the assistance of the mayor’s wife or Max. Still other books are acquired by Liesel alone. Each character has his or her own reasons for helping Liesel.
Other body paragraphs could be about Liesel’s choice of friends or her survival as her resistance against suppression. Liesel chooses Max as an intimate acquaintance and, later, as a possible love interest. This is certainly significant. Max, of course, is devoutly Jewish. Finally, the simple survival of people such as Liesel and Max can be evidence of resistance. The Nazi regime desires the suppression of resistance as well as the extermination of the Jewish people. The fact that both Max and Liesel survive can serve as evidence of their resistance as well.