People, Christians specifically, are often too easily offended by mockery.
But it is not necessarily a bad thing. It shows people are not indifferent: People only mock if they care. Something about you is bothering them. If they mock you as Christians, most likely something about our Christ is bothering them. Isn't it better that people are affected by Christ rather than indifferent to him? In my (although limited) experience, mocking is often the atheists way of asking questions, and we should follow the guidance of 1 Peter 3:15-16
Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect, keeping a clear conscience, so that those who speak maliciously against your good behavior in Christ may be ashamed of their slander.