There are two aspects that must be present in any thesis statement that is worthy of being written:
1. Textual Evidence
2. Specific Argument
Your thesis should include both textual evidence (some description of the text and what you think is important or interesting in it) and a specific argument (the argumentative context in which you are making some claim about what you have seen).
The argument should always answer the question “So what?” regarding the textual evidence. Do not just offer some facts about the text, or statements that cannot be debated. For example, “Elie Wiesel from Night struggles to survive” is self-evident and does not warrant an argumentative essay. No critical reader would bother to read such an essay since its central claim provokes no argumentative thought, which equates to little to no interest. If you do merely state a fact about the text, I will ask you “So what?” or, “What is important ABOUT the fact?”
For instance: if your thesis statement is something along the lines of: William Shakespeare’s Romeo and Juliet depicts opposing characters like Benvolio and Tybalt. I will point out that this is merely a factual plot reference, not a claim about the text; basically, no one who has read the story could reasonably conclude otherwise. You’re just telling me that Benvolio and Tybalt are contrasting characters, not what is important or interesting ABOUT the fact that they are opposing. (So what?)
But do not abandon this sort of sentence; after all, you have to begin by noticing something. Just make it the first part of your thesis:
The opposition of Benvolio and Tybalt in Shakespeare’s Romeo and Juliet. . . becomes the subordinate clause (the textual evidence) in your thesis statement.