If a person provides a good counterargument to your argument,you should revise your beliefs in light of this.

Critical thought is not a matter of seeking to establish the truth of the things you already believe. Rather, it is a method of carefully seeking to find out the truth. If someone is able to refute or at least throw doubt on your beliefs and arguments for those beliefs, then you should, as a good critical thinker, look to revise your beliefs in light of the new evidence.