If one wanted to name the most influential apologists of the twentieth century, both C.S. Lewis and Francis Schaeffer would be near the top of the list. If these two men have had an impact on you, you might be happy to hear that there is book that discusses both of them. Scott R. Burson and Jerry L. Walls wrote some years ago a book called C.S. Lewis & Francis Schaeffer: Lessons for a New Century from the Most Influential Apologists of Our Time.
In this book, the authors provide helpful biographical information and set these apologists in their cultural and historical setting. They do a great job of comparing and contrasting these men. While they have some things in common, there are other areas where they are very different (e.g. Reformed vs Arminian).
The authors take a look at some specific theological topics such as inerrancy, foreknowledge, epistemology and so on. To do so, they piece together ideas from a wide variety of writings and presentations. This study helps the reader to see the bigger picture of where they were coming from.
Having read this book, I have grown in respect for both men. I also found that reading this book provided great inspiration to strive for excellence in apologetics ministry. I highly recommend this book.