In the NKJV it reads a bit differently when it's set within the context:
"And who is he who will harm you if you become followers of what is good? But even if you should suffer for righteousness’ sake, you are blessed. “And do not be afraid of their threats, nor be troubled.
"But sanctify the Lord God in your hearts, and always be ready to give a defense to everyone who asks you a reason for the hope that is in you, with meekness and fear;
having a good conscience, that when they defame you as evildoers, those who revile your good conduct in Christ may be ashamed."
It seems that this is most important when we are opposed for our righteous conduct.
I first discern the intent of the one who asks me the questions: are the genuinely curious or do they have an agenda? From there, I might have a brief conversation or a long one. If they are sincere, I always leave it open for them to ask more questions. For the doubters, I might ask "What would convince you that God is real?"