Questioning your opinions is both good, and bad. On one hand, you should never be so confident in your own thoughts, opinions, and ideas that you’re never willing to examine them, listen to the ideas of others, engage in debate, and be open to changing your view.
On the other hand, when your thoughts, opinions, and ideas are based in genuine, empathetic, compassionate, and positive notions; when you have a solid foundation of knowing right from wrong, and why right is right, and wrong is wrong, then you need to be confident in those related thoughts, and ideas.