The Episcopal Church today approved a modernized version of its Book of Common Prayer, capping a 20-year process that has provoked controversy so bitter that some members have quit the church in protest.

Priests representing 107 dioceses voted to approve the new version of the prayer book. One dioceses' delegation of priests voted no and two others were divided. Among lay delegates to the church meeting, 99 dioceses voted yes, two no, and six dioceses were divided. The other half of the church's bicameral legislature, its House of Bishops, approved the new book on Tuesday by a near unanimous voice vote.

The revised prayer book, which has been in use in many parishes since it was tentatively approved three years ago, now replaces the 1928 version as the official statement of doctrine as well as liturgical practice for the church.

Although the convention complex here, where the triennial church meeting has been in session since Sunday, was saturated with flyers, posters, stickers and films opposing the prayer book revision, debate on the question was desultory. Both sides apparently had exhausted their energy on the emotionally charged issue.

In an effort to halt further schism, the House of Bishops yesterday recommended a set of guidelines that would not automatically discard the 1928 prayer book, but would permit parishes that prefer it to ease gradually into use of the new book. The lay and clergy House of Deputies is expected to act on the same resolution Thursday.

The revisions attempt to adapt the church, in both its language and concepts, to the changing conditions of today's world.

"The important thing about any worship is what we do outside the church afterwards," said Dr. Charity Waymouth of Maine, who seemed to sum up much of the argument for revision. "I do not go to my laboratory or my office or my store speaking Elizabethan English. I like to relate what I do in worship to what I do in life."

The Episcopal Church embraces a wide variety of liturgical styles from high church to low. In a not altogether successful attempt to keep everybody happy, the new prayer book offers a choice of formulations for the central liturgical functions of the church, including morning and evening prayer and the eucharist.

Rite I in the new prayer book is taken almost verbatim from the 1928 version with all the "thee's" and "thou's" and "goeth's" intact, while Rite II offers more contemporary language. The Psalms and many other portions, however, are included only in the updated version.

Such changes have infuriated some. "How chummy and informal it sounds to say 'you' to God," fumed one Texas woman in condemning the new prayer book. "There can be little doubt, I believe, that God cares how we address him," she added.

In accord with trends in church renewal in many Christian denominations today, the new prayer book invites more participation by lay members in both the traditional rites of the church and in new roles.

Included, for instance, is a new formula in which a lay person may hear a confession. Only a priest can give absolution, but in the alternate rite, another Christian may be asked to hear a confession. Instead of giving absolution, he or she merely recites the basic Christian tenet that God forgives sin.

The new book has been particularly criticized for changes in the marriage ceremony -- probably the most widely known ritual from the Book of Common Prayer. Only a contemporary form of the marriage ceremony is offered; the 1928 version is not included.

In the new prayer book the bride is asked to "love. . .comfort. . . honor and keep" her husband but no longer to "obey," a word which increasing numbers of couples have on their own edited out of the rite in recent years.

The archaic, if poetic, pledge of fidelity, "till death us do part," is replaced by "until we are parted by death."

In the marriage rite in the new book, giving the bride away becomes optional. That custom, observed the Rev. Dr. Charles Price of Virginia Theological Seminary, one of the authors of the new revision, "is a vestige of a time when women were considered to be property."

The double ring ceremony, which was not authorized in the 1928 book, is included also as a symbol of the equality of men and women, Price said.

The growing concern over the status of women also is reflected in a rite in the new book called Thanksgiving for the Birth of a Child. It takes the place of a traditional rite, called the churching of women, which had its roots in the ancient concept that women were ritually unclean after giving birth. The new rite celebrates the gift of the new life.