Writing in the Belfast Telegraph of Northern Ireland, Steven King makes this point.
Marriage is so central to Western civilisation that we rarely reflect upon its purpose.
It provides an anchor, if an arbitrary and weak one, in the chaos of relationships to which we are all prone. It provides a mechanism for emotional stability, economic security, and the healthy rearing of the next generation.
Governments rig the law in its favour not because they disparage all other forms of relationship, but because they recognise that not to promote marriage would be to ask too much of human virtue. Moreover, study after study shows that marriage is good for us. Married people are healthier, happier and live longer then single people.
Society has good reason then to extend legal advantages to those who choose the formal sanction of marriage over simply living together. They make a deeper commitment to one another and to society; in exchange, society extends certain benefits to them.
[. . .]
Gay marriage - and that's what civil partnership amounts to - offers gays and lesbians the same deal society has always offered heterosexuals: general social approval and specific legal advantages in exchange for a deeper and harder-to-extract-yourself-from commitment to another human being. The financial implications arising from divorce are the same, too.