Answer:
The theme is 'Persistence pays off'.
Step-by-step explanation:
We can see from the beginning of this passage that Moritz's goal was to overcome his fear of public speaking, and he did something important and brave to solve the problem that he had. He faced his fear because he joined the school's drama club. It the beginning, he probably had minor roles in the plays that drama club presented, but in the end, he got a big speaking role which shows us that his efforts and persistence really payed off.