As a Justice of the Peace and Quorum for my state I have officiated at quite a few marriages. My job, so to speak, is just as the witness for the State. The rules are quite complicated and I won't go into the myriad details, but I do not "marry" the couple. They marry each other.
The words I am required to say simply give the State's sanction. The two people enter into the contract.
It is my general feeling that if people knew more about contract law they wouldn't enter into the contract of marriage without very serious thought.
How about it Sparteye ... and all you Brothers and Sisters at the Bar?
If anyone interested, I can give you the shortest marriage form I know that is "legal" that is : recognized by the State.