Most people have at some level, an interest or curiousity in things that are considered 'spiritual'. Philip Zaleski has selected an excellent collection of essays and poems that reflect a wide range of spiritual-related ideas, musings, stories and expressions.
The number of essays is over twice that of poems but the volume of writing in the essays is probably fifty-fold that of the poems, so if you are looking for poetry, this is not the best source.
Keep in mind that the group is of 'spiritual' writing and not 'Christian', meaning that from essay to essay, idealogies will vary so much that at times you will wonder why they are even in the collection. Viewpoints move from naturalism to Buddism to Catholicism and more.
I found some of the essays very interesting. What will appeal to a different reader? It's hard to guess. But any reader with the slightest interest in things spiritual or spiritual people or other cultures are sure to find something he likes here.
Some of my favorites were:
The introdction
Physics and Grief
Judaism beyond Words
What The Blind See
As I said, the poetry is a relativly minor part of the collection. But of what was included, very little appealed to me.