No matter how you try to frame it, those who are opposed to gay or equal marriage are bigots. And just like all bigots, no matter the subject of their bigotry, they are doing their utmost to deny that they are motivated by prejudice - instead seeking justification for it in the Bible and/or a skewed view of morality and family values.
There is no difference between opposing gay people being allowed to access the institution of marriage and opposing black people, Asians, Chinese, or any other group in society being allowed to access it. The only thing that changes is the particular characteristic that makes them distinct as a group.
In the Deep South of the United States bigots and racists drew on biblical scripture as justification for segregation, Jim Crow, and the denial of civil rights to blacks. No one today in their right mind would even try and make the argument that blacks are not entitled to equality. Yet when it comes to equal marriage 175 Members of Parliament just voted against it, the bulk of them Tory MPs. This is a sad and scathing indictment, one that immediately exposes each and every one of them as unfit to hold elected office in 2013.
When it comes to the issue of providing legal sanction for an opt out of equal marriage on religious grounds, this is problematic on a number of levels. The Church of England, as the nation's established church, enjoys various benefits and privileges as a result of this status. It receives tax exemptions, property, and various other emoluments from the state. These are subsidised by the taxpayer, many of whom happen to be gay and/or people who support equal marriage. Why should they have to help fund an institution that denies them equality?
It is absurd.
The religious argument is largely, but by no means solely, based on an archaic and medieval rendering of the primary function of marriage as the production and rearing of children.
This antiquated interpretation of marriage falls down on a number of levels also. Firstly, it immediately posits the view that children born outside of wedlock are of lesser value than those born within. It also fails to take into account the fact that thousands of married couples are childless, many of them through choice. Does this then render their marriage any less valid than that of a couple which produces children?
Again, it is absurd.
It is also a dangerous to continue to uphold scriptural authority on issues that impact on society as a whole. The church and religion does not and cannot exist in isolation. Ever since the Enlightenment humanity has been engaged in a struggle against scriptural authority when it comes to the fight for equality, emancipation, and human rights. Whether it be over the right to vote for women, the rights of minorities, the struggle against the demonisation of sex, or the relationship between church and state, there has been an unremitting struggle against the constraints imposed on human progress by religion and the church.
Equal marriage in our time constitutes one of the last frontiers in this struggle. On a personal note, and speaking as a straight man, I do not believe in marriage. But I do believe that every one should be allowed to marry regardless of their religion, ethnicity, race, or sexual orientation. Being gay does not detract from an individual's humanity and need for equality and dignity. If the church is to be part of the human experience and not divorced from it, it has to shed every last vestige of the medievalism and bigotry which evidently still informs much of its outlook.
As for those MPs who have sought the sanction of scriptural authority to justify their bigoted attitudes towards gay people, they should be hounded from office as a matter of urgency.
Equality in society means nothing unless it is built into the institutions that underpin society. Anything less constitutes the legal and religious sanction of bigotry.