I think that there are many things in the New Testament that show us that the godliness of our conversation plays an important evangelistic role. The apostles are clear that we mustn't limit the explicit sharing of the gospel to formal preaching. It can also happen in ordinary conversations.
Mark DeverIf you think that the gospel is all about what we can do, that the practice of it is optional, and that conversion is simply something that anyone can choose at any time, then I'm concerned that you'll think of evangelism as nothing more than a sales job where the prospect is to be won over to sign on the dotted line by praying a prayer, followed by an assurance that he is the proud owner of salvation.
Mark DeverOur examples of enduring hardship are often more powerful than our stories of success and triumph.
Mark DeverThere is simply so much reason to believe the good news of Jesus Christ in history, in Scripture, as well as in our own experience that it would take a leap of faith not to believe in the gospel.
Mark Dever