My motivation for reading "Walking With Frodo" was primarily an interest in Tolkien's work, rather than in Christian devotion. "Walking With Frodo", however, is not a critique or analysis of Tolkien from a Christian perspective. Rather, the author Sarah Arthur uses Tolkien as a jumping-off point to discuss Christian themes. The book is primarily aimed at young people.
Given even this purpose "Walking With Frodo" does not work well. Ms. Arthur draws comparisons between Tolkien's work and Christian thought that are thin and conclusory. She begins, for example, by describing Gandalf's battle with the flaming Balrog. With no more support than that, she immediately tells the reader that of course the parallel creature in Christianity is Satan. (Tolkien was once asked if his work could be compared to Wagner's "Ring" cycle of operas. Tolkien answered that both works contained references to rings and that was the end of the comparison. The Balrog/Satan comparison strikes me as similarly light-weight.)
Ms. Arthur draws other comparisons and conclusions in a similar vein, using very little Tolkien material to support them. I find it hard to imagine that any young person with a good grounding in Christianity to begin with, is going to obtain anything more in this volume that could not be gained merely by reading the Bible itself or participating in related group activities. If the purpose is to attract young people who are LOTR fans to consider Christian values, I fear that any young person intelligent enough to read and understand Tolkien's work will see through "Walking With Frodo" as a thin attempt to tie Christian ideas to the coattails of Tolkien's current popularity.
I note also that although Ms. Arthur identifies Prof. Tolkien as a Christian, she does not mention that he was Catholic. (Likewise, C.K. Chesterton is identified as a Christian in a footnote, with no mention of his Catholicism.) While Protestants and Catholics may enjoy closer relations now, we know that this was not always so, either in this country or in Tolkien's time in Britain. We should remember that it was not too long ago that some Americans questioned whether a Catholic could lead this country as its President. In a book aimed at young people who may not be fully aware of the circumstances of Catholic/Protestant relations, (and as one who has had a Catholic education through college) I would have liked to have seen the fact of Tolkien's Catholicism mentioned.