Comment 8 by AtheistEgbert :

Marriage used to be a vow of loyalty between two people. Now it's been demoted to a contract, and as we know, all contracts require the interference and meddling of a third party, simply because it must! God is of course the most meddlesome of all, followed shortly after by the church and then the state.

I don't think I will ever get married in a legal sense, as I don't need a third party to tell me to be loyal.

No I don't agree. You have it the wrong way round.

Historically marriage was seen as a contract and sometime in the fifteen century the church started to impose its self as the guardian of marriage as a Christian institution as notions of romance started to take hold.

I would have thought the value of a contract would be obvious but I'll state the benefits as I see them. Assuming a marriage doesn't work out or one partner dies or is medically incapacitated ( in a coma say ) there is a good chance legal situations will arise that will require a court to make a decision. Without a contract these situations become less clear cut and become messy. Lots of more work for lawyers without a contract which is great for them but not for the plaintiffs. This also applies to state benefits, pensions etc.

Without a contract you are basically asking the state to make a decision about whether you are part of a partnership or not; which when you think about it is more of a responsibility for the state than being an arbitrator. For me the contract is the main benefit of my secular state marriage. I know that if I die things will be a lot easier for my wife, If I am in a coma she will decide my medical treatment not my family, if my wife dies I get automatic custody of our daughter and so on. I don't see fidelity or any other personal quality that you associate with it as relevant.