Ask a Catholic liturgist where Catholics find their identity, and the answer comes without hesitation: the Mass.

"It's where we are most 'Church,' if you will; where we are most the body of Christ," says Msgr. John Burton, chair of the board of directors of the Federation of Diocesan Liturgical Commissions. "The Mass is at the very heart of our Christian experience."

For Precious Blood Sister Joyce Ann Zimmerman, director of the Institute for Liturgical Ministry in Dayton, Ohio, the Mass is far more than a Sunday obligation or even a mere ritual.

"We cannot be Roman Catholic without Mass," she says. "Mass actually defines for us who we are as baptized members of the body of Christ."

And that, the two liturgists say, is why the Mass is so important to Catholicism.

Sister Joyce Ann notes that the Mass is where Christ gives himself to us in word and sacrament, offering his "total self-giving love" that marks his divinity and humanity. "That total self-giving is what our life as baptized people is also all about," she says. At Mass, "we enter into and rehearse who we are to be and how we are to be as the visible presence of Christ in the world today."

Catholics' participation in the celebration of the Mass is a celebration of salvation, says Sister Janet Baxendale of the Sisters of Charity, a professor of liturgy at St. Joseph Seminary in Yonkers, N.Y.

"This is one of the primary reasons that the Mass is at the center of our life as Catholics," Sister Janet says. "The bread and wine offered on the altar truly become the body and blood of Christ which was sacrificed for our salvation. This Eucharistic food nourishes us spiritually. It is our food for the journey of life."

The three liturgists note that upcoming changes to the English translation of the Roman Missal will likely cause concern among some because of the deeply personal way in which the Mass touches people.

Some tend to become very protective in the face of change, Sister Joyce Ann says. But the liturgy is a communal gathering and not an individual event. When a person comes through the church doors and enters the sacred space, they leave the individual self outside and join the gathering as members of the body of Christ, becoming "we" instead of "I," she says. The realization that the "liturgy isn't about me" should help people prepare for the changes, she says. They have to "let go" and place their trust that the Spirit and the teaching office of the Church will be moving them forward.

The new changes are not being made for the sake of change but to be as "faithful as possible to the Latin texts from which they were translated," Sister Janet says. While they may take some getting used to, "they can be for us a way to grow in a deeper understanding of and appreciation for the power and beauty of the great treasure we have in our Mass."

The three liturgists note that the Mass, as the summit of all the Church's services, differs from the other sacraments and popular devotions such as the rosary, Stations of the Cross, novenas and other forms of private prayer.

"Both private prayer and popular devotions are strongly encouraged by the Church," Sister Janet says, but "while they are a help to our celebrating liturgy well -- to putting us into the spirit of the liturgy -- they are in no way equal to the liturgy."

Msgr. Burton likes to look at the Mass from a monastic perspective, where the Mass is at the center of the day and everything leads to it and flows from it.

As Catholics, all of life leads to the Mass, he says, and "all of life leads from it."