"But in your hearts set apart Christ as Lord. 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." ~ 1 Peter 3:15-16
One brother whom I know from the Cyberspace introduces this Free Online Book, "Foolish Faith" to me. You can read it by clicking on the book title. Personally, I find it worth a read even though I have only browse through it briefly.