You won't be able to attend Mass the same way after you've read Deacon Owen Cummings' new book, Liturgical Snapshots (Paulist Press, 158 pp., $16.95).

Cummings, a theologian and dean at Mount Angel Seminary, also writes the Catholic Sentinel's regular question and answer column. More to the point, he's a husband and father of five whose workaday experience makes his work meaningful in everyday life. 

The amiable Scotsman writes about our worship not only with insight, but with good humor and compassion about the human condition. Along with St. Augustine he is convinced that we are restless until we rest in God. He understands that we try a lot of dumb things first. 

Liturgical Snapshots begins where all Christian thought should — with the Trinity. But this is no far-flung attempt to explain the mathematics of mystery. Cummings says liturgy is nothing less than the moment we encounter the lavish and abiding invitation to join the Trinity's loving communal life. 

"The liturgy, the entire economy or history of salvation, indeed creation itself, is about God's deifying us, about our participation in God," Cummings writes. "The Communion that is God is not content to remain in God-self."

So much for thinking about football during Mass. 

Cummings operates from an admirable blend of scholarship and accessibility, a rare feat in a world prone to indecipherable theology and fluffy religious blogs. 

The book's chapters may at first glance seem only remotely linked, but Cummings' treatment of each section is consistent: sensible, enthusiastic, optimistic — never naive. His methods unify the book. And so does his conviction that theology of liturgy has not kept pace with liturgical renewal. His writing gives that body of thought a nice boost.   

One fascinating essay explains how the movements of the liturgy are based on the movements of human social life. Eucharist, Cummings says, can help tired and anxious people re-focus on what it means to be truly human. 

Prayer, worship and even hearing scripture are communal, not individual acts, he reminds us.   

A welcome section points out the Holy Spirit's presence in the Eucharist, which we Roman Catholics have under-valued, preferring a historical and christological view.

The Counter-Reformation's Council of Trent (1545-1563) has become a pariah for some Catholics. But Cummings insists it had some very good ideas, including the notion that the real presence of Christ in the Eucharist is not limited to the eucharistic gifts, though that is the presence par excellence. Christ is also present in the liturgical assembly, the Word of God and presider. Such insight, which has been muted since Vatican II embraced it, will change the way people engage in Mass. 

Other chapters take up preaching, benediction and the origins of the Eucharist. Cummings tackles some of the most pressing questions with common sense — Do prayers change anything? Is it all right to ask things of God? What does the Eucharist say about God and the existence of evil? He reflects on death and "God's lovely presence." 

Because Cummings is not plying new ground, but instead tidying up centuries of thought, his easy but disciplined ways bring coherence. He uses terms like "oodles" or "warp and woof" and cites West Side Story in a section on marriage. He is neither progressive nor utterly traditional — he's prudent. Most of all, his enthusiasm for God is catching. 

In this, his 15th book, he calls on a cloud of distinguished witnesses, citing the poet George Herbert, Cardinal John Henry Newman and various novelists, preachers and contemplatives. 

In 2008, Cummings received the papal honor Pro Ecclesia et Pontifice from Pope Benedict and Archbishop John Vlazny. Liturgical Snapshots is dedicated to Archbishop Vlazny and Msgr. Richard Paperini, former president-rector of Mount Angel Seminary. 

Cummings' book deserves great merit for consolidating in an approachable way some great theology on liturgy and sacraments. He never intended to be comprehensive. But we can trust and enjoy the choices he made in 158 pages.