If the gospel were a truth that could be known in general, then there would be no necessity to witness. All that would be necessary would be to confirm people in what they already know. If the gospel were about general, unavoidable human experience, then it would not be necessary to be confronted by anyone as odd as a Christian. But because the story we tell of God is the story of the life and death of Jesus of Nazareth, the only way to know that story s through witness.
“On Witnessing Our Story: Christian Education in Liberal Society” 231