I recommend this not so much because of the writing quality (which is so-so) but because this book was the Christian fiction bestseller of the 1980s. It sold more than 1.8 million copies in trade paperback, 90% of which were sold through Christian bookstores (and industry figures show only 10% of Christians ever walk into a Christian bookstore.) Why? Because people are desperate for a book to read after they've finished C.S. Lewis! If you want to write SF/fantasy from a Christian perspective, you need to pay attention to this book!