NEW YORK — Three theologically conservative Episcopal dioceses will soon vote whether to secede from the liberal church in a dispute over how they should interpret what the Bible says on many issues, including homosexuality.

In 2006, the Diocese of San Joaquin, based in Fresno, Calif., became the first to break away. The Diocese of Pittsburgh plans to vote on secession during a meeting today. Dioceses in Quincy, Ill., and Fort Worth, Texas, are set to cast ballots on withdrawing next month.

At stake is church unity, tens of millions of dollars in Episcopal assets and the shape of Episcopal relations with the rest of the world Anglican Communion.

The 77 million-member fellowship, which includes the Episcopal Church, has roots in the missionary work of the Church of England. Most overseas Anglicans believe Scripture bars gay relationships, and some Anglican leaders have intervened in the U.S. on behalf of conservatives.

Here are the key issues behind the votes:

Q. Why are Episcopal dioceses considering secession?

A. Episcopalians have been divided for decades over what Scripture says on many topics, including salvation through Jesus, Christ's resurrection and gay relationships. But the rift broke wide open in 2003 when the Episcopal Church consecrated the first openly gay bishop, V. Gene Robinson of New Hampshire. Some Episcopal conservatives said they could no longer remain with the denomination.

Q. What happens when a diocese secedes?

A. The breakaway Diocese of San Joaquin has affiliated with the conservative Anglican Province of the Southern Cone, based in Argentina, in an effort to remain Anglican. Other seceding dioceses could do the same.

Q. What happens to parishioners who want to stay with the Episcopal Church?

A. In San Joaquin, parishioners aided by the national denomination elected a new Episcopal bishop to reorganize the Episcopal diocese alongside the breakaway diocese. The national church meanwhile sued the breakaway diocese for control over millions of dollars in parish assets. In Pittsburgh, parishioners opposed to secession have spent years planning how they can reorganize their diocese and parishes, and maintain service programs, in the case of a split.

Q. Is the entire Episcopal Church coming apart?

A. No. Most of the 2.2 million Episcopalians don't consider their theological differences cause to leave the church. Although the exact figure is in dispute, Episcopal leaders say that less than 100 of their more than 7,000 parishes have voted to split off since Robinson was elected. Still, it's a significant blow when even one of the 110 dioceses walks away and tries to take church assets along. Secessions can lead to complex, costly legal fights.

Q. Are other denominations facing similar conflicts?

A. Yes. Several mainline Protestant groups, including Presbyterians, Methodists and Lutherans, have also wrestled for decades with how they should interpret the Bible and whether they should accept same-sex partnerships. Leaders of those denominations are monitoring the Episcopal situation for any lessons on how they can handle their own differences.