Something that makes no sense at one time can make perfect sense at another. I just reread the mystical classic The Cloud of Unknowing and found it rich with spiritual insights. Apparently I did not think so some years ago. As I savored the book recently, I kept bumping into margin notes scribbled in my handwriting, most of which contained emphatic question marks and other signs of confusion and disapproval.

The two subjects of this review are classic expressions of Christian spirituality, but readers who find The Holy Longing enriching probably will be disappointed with Satisfy Your Soul. And readers who relish Satisfy Your Soul will be confused by The Holy Longing.

That's because these two new books understand Christian spirituality in markedly distinct ways.

Satisfy Your Soul is by former (self-admitted) rationalist Bruce Demarest, professor of theology at Denver Seminary. It is partly a spiritual autobiography, describing his move from a faith centered on doctrine and action to one that now includes the spiritual and experiential. It's also an argument for the validity and necessity of evangelicals' pursuing spirituality.

The Holy Longing is by Canadian Ronald Rolheiser, a member of the Missionary Oblates of Mary Immaculate—in other words, a real Roman Catholic. Rolheiser wrote his book to help anyone struggling with spirituality, but especially those inside the church (and not just the Catholic church).

Demarest, in spite of his significant journey toward spiritual experience, remains a theologian at heart. He spends a lot of pages arguing the legitimacy of spirituality and helping readers discern true and false spiritualities. For example, he warns that the "Labyrinth Walk"—in which people walk ...