I'm intrigued by this concept and would like to know more. However, I can't find much about it anywhere on the internet. My ignorant interpretation of the term would be that it's similar to what nuns and priests do yes? Marry themselves to their god and such? I really have no idea, but I'd like to.
Catholics for example, teach the catechisms before a person is confirmed Catholic. Holy Communion to the Spirit is performed usually around the age of 8-10 years old. Young women are dressed in a traditional White (Virginity) wedding gown and young men in tuxedos. See: Holy Communion
Children at that age rarely understand the full gambit of what ideologically their parents are guiding them to do. From a familial aspect, it deals with religious moral ethic. In order to achieve salvation, one must commune with the Spirit. When I was a child, it was still referred to as the Holy Ghost, the ethereal disembodied God, seeking the Sacred Heart as host. In other words, it's a voluntary possession Ritual. Even if young children do not understand this. Parents usually expect it of their children, much like it was expected of them when they were children.
The Confirmation is designed for this purpose. By late adolescence, there's a deeper understanding however the indoctrination process (Initiation) begins in early childhood development. Most children Confirm as Catholics. For myself, I was well aware of the Communion ritual and its purpose and in spite of personal protest, I was forced to undergo it by my parents. I did not however confirm. If I believed in displaced spirits, the next step would be an exorcism or the Un-Baptism Rite but that's for the believers and people with religious baggage. My choice was in essence reclaiming my ability to make decisions on my own behalf.
This is merely one example of the Godspouse, there are many others from various cultures which essentially serve the same purposes. It's part of the Initiation Process.
Here's an FAQ on godspousery that might be of interest: http://lokisbruid.wordpress.com/godspouse-faqs/.