Does same-sex marriage show Church and state cannot sing from the same hymn sheet?

One important conflict between Church and state in which there is much contemporary interest centres on same-sex marriage. More and more states are reforming marriage law to allow for same-sex marriage in the secular context. The extension of equal marriage from the secular to the religious context, however, remains fraught.
We respond to three arguments against same-sex marriage within religious contexts. The first says that same-sex relationships fail to realise the value of marriage because they do not lead to procreation. The second says that the attitudes expressed in a religious text justify not accommodating same-sex marriage. The third says that making marriage available to same-sex couples induces a change in the meaning of ‘marriage’. We argue that none of these arguments succeeds. Religious representatives should, if they are open to reasons (see §3), endorse same-sex marriage.
Nevertheless, we argue that the state should allow individuals who perform religious marriages the option of declining to marry same-sex couples. This is because of the special role of sincerity in performing a marriage. The requirement of sincerity distinguishes the case of marriage from cases where a couple’s right to equality of opportunity is violated, e.g. where an hotelier refuses a room to a couple because they are of the same sex. Representatives of a religion who believe that marriage is unsuitable for same-sex couples, however poor their arguments, are incapable of performing same-sex marriages. In that case, they should not be subject to state sanctions for refusing to marry a same-sex couple.