Someone just sent me a message and I don't think I should respond, what do you think?
Well, could you tell me why exactly you don't want to respond?
The person is being rude.
You should respond to messages. Even if the person is rude, you shouldn't just ignore them.
What would you do in this situation?
I would respond and just tell them that they are being rude and ask them to tone it down. You shouldn't just outright ignore a message sent for you.