My evangelism professor in seminary was Jack Miller.  He not only believed the gospel, he loved the gospel.  He was gospel-centered and from that center he overflowed with joy and love.  He was also a risk-taker.  He believed the words of Paul in Romans 8 that if God has given us his Son then we can face death all day long.  We can take risks for Jesus’ sake and Jack did.  I am not sure how anecdotal this account is but I was told that he would often go up to a complete stranger and introduce himself by saying, “Hello, I am Jack and I am a recovering Pharisee.”