Religion is a major contributor (and possibly the biggest) to "anti-gay hate." In fact, Andrew L. Whitehead of Baylor University believes there would still be unfavorable attitudes towards same-sex couples. This belief is backed by scientific evidence of one's sexual orientation being biological.
Whitehead also notes some interesting psychological studies that affect how people view gay men and lesbians. One theory, known as the Attribution Theory, states that people see behaviors as being either controllable or uncontrollable. If the person in question is shown to exhibit one that is believed to be governable they are usually more negatively looked down on than if the behavior is seen as ungovernable. This is an interesting fact to consider, because almost all religions believe gays choose their sexual orientation. Religions do not recognize that being gay could be a biological condition which one cannot control. It just so happens that many religions find gays to be deliberate sexual sinners.
View of Evangelical Christians
Studies show that Christians with a literal view of The Bible and angry/active views of God tend to have more anti-gay beliefs than their counterparts. It depends on how enthusiastic one is in their own religion. If one is more active in their congregation, they are more likely to oppose gay marriage.
View of The Church of Jesus Christ of Latter-day Saints
The Church of Jesus Christ of Latter-day Saints is completely opposed to gay marriage. One of its beliefs is that marriage is only ordained of God if it is between a man and a woman. The Family: A Proclamation to the World states, "...marriage between a man and a woman is ordained of God and that the family is central to the Creator’s plan for the eternal destiny of His children."
It is obvious that this particular religion is against gay-marriage. Many people have criticized them for stating that they stay out of politics. However, in the case of proposition 8, they did not. This is an invalid argument because the church has only vowed to be politically-neutral in party politics, not in passing laws.
It was not unconstitutional for The Church of Jesus Christ of Latter-day Saints to promote the passing of Proposition 8. There is nothing in the constitution that states that there should be a separation of church and state. Not that it was right of the church to advocate a law that would restrict other's rights, but it was their decision to advocate it.
The overall message is referring to a talk that Elder Packer gave in the a session of General Conference in October 2010 in which he gave a rather harsh talk, in the views of many, against same-sex attraction. In his talk, he stated that same-sex attraction is something changeable and that should be changed.
View of Muslims
Gay marriage is not permitted in Islamic beliefs. The Qur'an states that it is a transgression for males to have sexual relationships with other males. This holy text, however, is not the only entity of the Muslim religion that outlaws gay marriage. The religious leader Muhammad and Islamic law also forbid it.
According to professors, Rusi* Jaspal and Marco Cinnirella in the article "Coping with potentially incompatible identities: Accounts of religious, ethnic, and sexual identities from British Pakistani men who identify as Muslim and gay", many Muslims see same-sex attraction as westernization, which comes from living among those with "lower values."
Islamic law and the Muslim religion call for capital punishment of gays who participate in intercourse with the same sex. Today, many of the Muslim countries do not carry out this punishment. Instead, sexual minorities are often marked with a gay slur on their records when caught in the act by the police.
Views of Catholics on Gay Marriage
Catholics, like the other religions, are doctrinally against having sex with the same gender and gay marriage. However, they are not against being a sexual minority in general. The article entitled "For Catholics Open Attitudes on Gay Issues" points out that Catholics are one of the most progressive religions as far as gay tolerance. The article also points out that Catholics are more likely to be in favor of allowing gay marriage than their Evangelical Christian counterparts. They are also more likely to have religious leaders of higher tolerance and sensitivity to gays in their congregation.