Firstly, we note that it is already legal for gay partners to enter into civil partnerships, as sort of secular contracts, and if that is what humanists and secularists want then it doesn't have an impact upon the spiritual aspect of human life. In an open society we do not oppose secular civil partnerships if that is what people living in the world want. However, we would suggest that a secular society has all it can want in the concept of civil partnerships, so why try and change the meaning of marriage, if it is not an attack on religious belief and religious communities?
We need to recognise that marriage is a covenant relationship between a man and a woman that has a spiritual dimension - it transcends, or goes beyond, secular civil contracts (even if unrecognised by participants) - as the saying goes, 'marriages are made in heaven.'
Of course people may point out that not all cultures have upheld monogamous marriage between men and women. Some religions allow a man to marry four or more women, and even homosexual marriage has been known in the past. The Greeks and Romans allowed such marriages, Nero for instance married a male freed slave, but it often also occurred between grown men and young boys. However, Rome was a brittle kingdom and struggled to maintain social cohesion due to its brutality and inconsistencies (Nero also murdered his own mother and wife).
The lesson from this is that if secularists and populist governments seek to overthrow the order that Christianity brings to society, for instance by undermining the Mosaic ordinance of marriage, it will be sadly Britain that collapses, and not the Church which will stand as a beacon of hope in the darkening land. By undermining Christian values and principles, for instance in marriage, what principles will society have other than those based upon fickle human sentiments?
We are not to be slaves to our thoughts and feelings; instead we are volitional beings. So we do not believe that people are born gay, but gay sentiment arises through other factors, particularly through biased media propaganda that closes down honest debate. ‘Gayness' then is not intrinsic to the human condition, but is extrinsic and arises according to a lifestyle choice. It cannot then be a human rights issue.
Marriage is a sacred union between two human temples, one man and one woman, for the purpose of bringing forth children. One wonders about the arrogance of politicians who think they can alter divine law.