LOS ANGELES (AP) -- Prayers ingrained in the memories of millions of U.S. Roman Catholics would change under a proposal American bishops were considering to tweak the Mass so that it adheres more closely to the Latin version.

The U.S. Conference of Catholic Bishops was planning to vote Thursday at its biannual meeting on a new translation for the Order of the Mass -- an effort to satisfy Vatican calls for a more accurate translation.

The changes would be the most significant to the Mass since parishioners first began worshipping in English instead of Latin following the Second Vatican Council of the early 1960s.

The new translation would the alter the wording of 12 of the 19 texts spoken by Catholics during worship, including the Nicene Creed, the Gloria, the Penitential Rite, the Sanctus and Communion.

But some worry about changing a fundamental rite of worship that is so much a part of Catholic identity, especially now. Mass attendance has been declining, the priest shortage has left a growing number of churches without a resident cleric, bishops and parishioners have been battling over the closure of old churches and schools, and the prelates have been trying to rebuild trust in their leadership after the clergy sex abuse crisis.

"It's going to cause chaos and real problems and the people who are going to be at the brunt end of it are the poor priests in the parishes who don't need any more problems," said the Rev. Thomas Reese, a senior fellow at the Woodstock Theological Center at Georgetown University and a Jesuit priest.

The Vatican recently issued updated guidelines for the translation of the Latin texts that aim not only for accuracy but for "a deeper language that's more expressive and more poetic," said Monsignor James. P. Moroney, who leads the liturgy office for the bishops' conference.

Minor changes to the wording of many portions of the Mass will be obvious to Catholics. The repeated exchanges "The Lord be with you" / "And also with you" between a priest and his congregation, for example, become "The Lord be with you" / "And with your spirit" in the updated version.

The prayer said before Communion would become "Lord, I am not worthy that you should enter under my roof," instead of "Lord, I am not worthy to receive you."

Survey results released by the conference's Committee on Liturgy last November found that U.S. bishops were split over whether the changes were necessary.

Two-thirds of the U.S. conference's 254 Latin-rite bishops must vote to approve the new Order of the Mass for it to pass. It would then be forwarded to the Vatican for final approval before Mass at the parish level would change.

Bishop Arthur Roche of Leeds, England, the chairman of the International Commission on English in the Liturgy, told the bishops Thursday that the translation after the Second Vatican Council was rushed and now "we are teaching ourselves and our people to speak Bible."

If the U.S. bishops do not approve it, the translation will likely go back to the bishops' liturgy committee for more revisions before another vote later this year, Moroney said.

Before the meeting began, members of Voice of the Faithful and the Survivors Network of Those Abused by Priests held a news conference to criticize the U.S. bishops for not doing more to prevent clergy sexual abuse. They called for full funding and completion of a study the bishops authorized on causes of the abuse crisis, which continues to drain the U.S. church financially.

"So much of the Scripture is empty without the actions and if we want our liturgy to be Spirit-filled, it can't be without action from the bishops," said Gaile Pohlhaus, Voice's secretary and a theology professor at Villanova University.

Inside the meeting, the new Vatican nuncio to the United States, Archbishop Pietro Sambi, expressed empathy for the bishops and the reputation of the American church, which he said had been unduly tarnished by the crisis.

"The great majority of (the prelates) were not bishops when it happened," said Sambi, who received warm applause at the end of his remarks. "They have to face difficulties and sufferings for a responsibility that is not upon them."