The essence of evangelism is the gospel message—true for all peoples, all places, and all times. Sam Chan, a practicing medical doctor and a public evangelist with City Bible Forum in Sydney, Australia, recently wrote Evangelism in a Skeptical World: How to Make the Unbelievable News about Jesus More Believable. Below, I talk with him about his new resource. Ed: Why a book on evangelism? Sam: Deep down, every Christian wants to tell his or her friends about Jesus. But we also know just how unbelievable the gospel—about a man called Jesus, who is both God and human, who died…