There's a difference between being able to "give a defense" and being defensive. Unfortunately, too many believers take it personally whenever someone questions their faith. They forget that it is not our responsibility to win anyone to Christ ("No one can come to Me unless the Father who sent Me draws him," said Jesus in John 6:44). Our responsibility is simply to tell others about the Lord. We should have no performance anxiety or notches on our gun. Saving people is what God does. Telling people is what we do.
Giving a defense for the hope within us, then, is inextricably tied to knowledge — knowledge of God, His word, and of our experience. I refer to knowledge of our experience deliberately. Sometimes people will say, "I know that I know that I know..." — which means, "I know, but I don't know why." Peter is saying that's not good enough. We've got to know why. We've got to be able to give a reason (NIV) for the hope that we have. This means we've got to engage our minds with God's word, with God's Spirit, and with ourselves, thinking through what it means to be a believer. It's not enough to say, through our lack of thoughtful preparation, that "You should believe because I do."
Rather, we've got to be able to say, "I believe, and here's why", rightly "dividing the word of truth" (2 Tim. 2:15). And we should do so "with gentleness and respect" (v.15 NIV).
Lord, give us grace to be diligent to present ourselves "approved unto God, workers who do not need to be ashamed, rightly dividing the Word of truth". Give us the ability to express to others our faith in Jesus Christ with all boldness and fervency.