Are you with any particular denomination?

I have been asked or heard people ask what denomination I or another group was associated with many times. All separate instances by completely different people. Each time I was with a different group, so the answer varied accordingly. However, each time it was asked there were two common denominators. One, the group asking. Two, the motivation in asking.

The group inquiring on the issue has always been a group that does not consider themselves a denomination. They take pride in being "Christians only, not the only Christians." I am currently attending one of their colleges where I am enrolled in a history class that covers the formation of their movement. I am finding it very interesting learning about the influences of thought during the 18th and 19th centuries and how it relates to today. I am also finding great delight in Christians of yesteryear that fought so hard to shake off their denominational heritage. I consider myself one of these few that are Christians, period. I am finding it slightly ironic that a group of Christians that teach unity of all believers would inquire so heavily on various others beliefs.

Maybe I should clarify why they were asking. As I said, the motives were all the same. They were all asking because they wanted to know if our doctrines were such that they agreed, or at least could give permission to usage of their facilities or partnership. In a few cases it was a denomination seeking usage of space for a group to meet. They sought knowledge of the groups beliefs to see if they were in accord with ___________(their creed? I thought they didn't have any creed but the Bible.) In one instance, the group was denied. In another it still has yet to be determined. The other cases involved partnership, teaming up with other believers to reach a greater radius. One was a misunderstanding, in which a single person thought he was going to be working with a particular denomination that he couldn't support. However that denomination did not in fact have any presence, but merely gave resources to the group that this man was working with. In other words, the denomination that this gentleman didn't want to work with was sharing their tools with others in the Kingdom. In another circumstance, a group of churches were working together in a local area that was in chaos after a natural disaster. A few churches were not involved with the joint effort, one being part of this movement. I as an intern of this church that valued unity, took it upon myself to see what united front there was in rebuilding this area. I was pleasantly surprised to see many working together and offered the assistance of our church in the effort, for we were very much there. However, when my boss (not God), found out about my efforts in building unity with other groups, he ignored it, saying that they were groups that he couldn't support.

I have two questions. 1) Are the many thousands of denominations treasured by God as His church?
2) If they are, who are we to not support them?