I heard Dr. Alfonso Espinosa interviewed on Issues Etc as part of a series on his new book, Faith the Engages the Culture. This is the second book in what is to be a trilogy on the topic of Christian witnessing in the world.
I have not read this book but have his first book, Faith that Sees through the Culture. Concordia Publishing House (CPH) offers a free video course on this first book which establishes the perspective on how Christians need to look at the world they are in. This book establishes the foundation for stepping off into the second book.