Christianity and homosexuality
Classical and modern-day Christianity holds that homosexual behavior is a sin, based on such Biblical passages as Leviticus 18:22 ("You shall not lie with a male as with a woman; it is an abomination."). Romans chapter 1, and the Ten Commandments prohibition on adultery, and other verses have traditionally been understood to prohibit any sexual activity that is not between husband and wife (see Fornication).
This position is accepted as virtually indisputable among most of Christianity's hundreds of denominations worldwide (or thousands of denominations, depending on how one counts splinter-groups.) The Christian theological arguments against homosexual acts rest chiefly on the specific verses held to prohibit the act, as well as the general restriction of all sexual activity to that between husband and wife.
Modern Liberal Christian views on homosexuality
Whether homosexuality is a sin has become a topic of hot theological debate among Christians in the half century since World War II. Many liberal Christians in American and Europe are moving towards a view that no longer considers homosexuality to be a sin; most others retain the traditional Christian view, which holds that homosexuality is a grave sin. Among Protestants, this traditional view is generally strongest in the US, while American Catholics are typically more liberal than Catholics elsewhere.
Many Liberal Christians point out that Leviticus also condemns many other things that modern Christians do, including eating shellfish, wearing fabrics made from two different fibers (e.g., wool/cotton blends), and planting two crops in a single field. This is because Leviticus contains a mixture of "moral" codes and "purity" codes. (Jews hold the Bible actually makes no distinction between morality and purity, and that the rules were generated in such a way that following the purity laws would lead to ethical behavior.)
The purity code prohibitions are not considered to apply to Christians because they have been superseded by the sacrifice of Jesus. However, the moral codes still apply. Traditional Christians consider the Levitical condemnation of homosexuality to remain in force, even though it appears in a list of purity laws because it is reinforced elsewhere in the Bible, and in particular in the New Testament.
Most traditionalists view homosexual behavior as a freely made choice, and believe that it is possible and desirable to transition to heterosexuality. This view is strongly rejected by most psychologists and many scientists. However, most Christians who condemn homosexual behaviour would not condemn homosexual orientation, and would advocate a life of celibacy for those of homosexual orientation.
Liberal Christian theologians who do not believe homosexuality to be a sin argue that the traditionalists have misinterpreted the pertinent Bible passages or quoted them selectively. For example, they consider the original Hebrew in Leviticus to be ambiguous as to whether "male" means adult man or boy. The fact that Leviticus prohibits several activities that are nowadays accepted (i.e. the "purity" codes), such as shaving, is also sometimes presented as a counter-argument. Similar critiques are made of other verses.
They also point out that Jesus explicitly condemned divorce -- equating it with adultery in the Sermon on the Mount -- but never explicitly forbade homosexuality; so they call it hypocritical to criticize homosexuality much more vocally than divorce.
Also, rather than interpreting the term "adultery" in the Ten Commandments to mean any sex outside of marriage, they interpret it to mean sex with somebody else's spouse, which would make the prohibition irrelevant to sex between unmarried persons, including sex between unmarried homosexuals.
Modernists often argue that homosexual desires are present in a person at birth or in early childhood (see Genetic basis for homosexuality and Causes of sexual orientation. They further argue that to deny people the right to express romantic love with another human being in the manner that God endowed them with is not an act of compassionate love. Many theologically liberal Christians agree and believe that God wishes the person to fulfill these inborn desires.
Positions of specific churches
The Roman Catholic Church considers homosexual behavior a sin, but has clearly stated that homosexual desire itself is not.
The Episcopalian Bishop John Spong has argued extensively in favor of the view that homosexual behavior is not a sin, in disagreement with much of the Anglican Communion, both domestically and abroad. Some bishops have openly disregarded the viewpoints of church leaders, ordaining homosexual rectors within their diocese, causing debate within the church. However the majority of the Anglican Communion, in particular the African churches, maintain the traditionl view that homosexual behaviour is a sin. Many (most?) Christian reject Spong's arguments, because Spong denies the existence of the Trinity as literally real, denies that Jesus was literally was the son of God, and denies the existence of a theistic God; instead he affirms instead a monotheistic deism. Thus his critics argue that he is no longer a Christian but rather a deist, and his beliefs have no bearing on those who hold by Christian theology.
The Church of Jesus Christ of Latter-day Saints considers homosexual behavior to be sinful, as are any sexual relations outside a lawful marriage. Homosexual desire itself (if not acted upon) is not viewed as sinful and is sometimes referred to as same-sex attraction (SSA) rather than homosexuality. The church has actively opposed efforts to legalize same-sex marriage, although it has not taken any formal position on other political matters affecting legal rights for gays.
The United Methodist Church officially considers "the practice of homosexuality (to be) incompatible with Christian teaching" and states that ";self-avowed practicing homosexuals" cannot be ordained as ministers. However, some local congregations have defied the church leadership on this issue and are fighting the policy in church courts. Politically, the church has supported civil rights for gays, although it is unclear whether that support extends to same-sex marriage.
The Presbyterian Church (USA), the largest U.S. Presbyterian body, is sharply divided over the issue of homosexuality. Although gays are welcome to become members of the church, denominational policy prohibits noncelibate homosexuals (or unmarried people who are sexually active) from serving as ministers or on key church boards. After rancorous debate, that policy was upheld in a vote of presbyteries in 2002. It is uncertain how those on the losing side will react; some observers believe that congregations could break away from the denomination over that issue.
The Seventh-day Adventist Church condemns homosexual relations as "obvious perversions of God's original plan."
Unitarian Universalists do not believe homosexuality to be a sin. They ordain gay and lesbian ministers, and welcome gay people into their congregations both informally and formally. The Unitarian Church itself has stated that it is no longer a part of Christianity, although many Christians are members of the Unitarian church.
The Lutheran church (at least in Germany) ordains gay ministers and does not condemn homosexual behavior in any way.
See also: Religion and homosexuality, Homosexuality and morality, homophobia