The Scottish Government's decision to become the first part of the UK to introduce gay marriage is an important cultural, moral and social moment in the history of this country.

Less than a decade ago gay couples in committed relationships had none of the legal rights of married heterosexual couples. Now there is to be complete equality for the first time, with the UK Government indicating it will soon follow suit. Surveys of public opinion have shown for several years now that most Scots are in favour of this reform, albeit that the consultation on the subject showed 64% against. In making the decision to change the law, the Scottish Government has made a bold decision.

It has been hard for the Government to reach this point. Some religious groups in Scotland, including the Roman Catholic Church, the Church of Scotland and the Muslim community, have been consistent in expressing their profound opposition to gay marriage; it is contrary to their religious beliefs and their definition of marriage as between a man and a woman.

In response to this, the First Minister and the Government have said they respect these views, which is how it should be. If there is to be freedom of gay people to marry each other then there must also be the liberty to express and practice religious beliefs. Therefore, it is right that the Government has expressed its intention to protect the right of religious groups to refuse to marry gay people in their places of worship.

However, the issue for the Catholic Church in particular has been that, in expressing this view, it has sometimes used language that has not helped its case and this would certainly apply to the comments by the Archbishop elect of Glasgow, Philip Tartaglia, concerning the death of the Labour MP and former priest David Cairns.

If progress is to be made on how the law on gay marriage proceeds from here, it must be based on rational debate. If religious leaders lose sight of this, they are in danger of undermining their voice among the range of views on this subject.

In framing the new law on gay marriage the Scottish Government must try to reflect all of these views and protect the rights of gay people and Christians, but on the issue of marriage there appears to be a settled view: legally enshrined discrimination is no longer acceptable. When the law was changed in 2005 to introduce civil partnerships, thousands of couples made a public commitment to each other for the first time. But, for many, the civil partnership remained a second-class arrangement.

In changing the law on marriage, Scotland will be added to the list of progressive democracies that have made this move. In making such a public statement at the time of heightened emotions around the issue, the Government has also said it will not tolerate inequality. This should mean that no-one will be required to act against their conscience or religious beliefs. But it also means that Scotland has said to all of its citizens: on the issue of marriage, everyone is equal.