denomination, sic.."A large group of religious congregations united under a common faith and name and organized under a single administrative and legal hierarchy." So, I would think yes you could be. What I meant was that an argument could be made that one cannot be 'christian' without belonging to some sort of community of faith.

As for churches that call themselves 'just'a Christian church. to be honest I am not sure I can be objective..it does seem to me to smack a bit of hubris? Common Ground? obviously I doubt that I,as a Roman Catholic and believer in Dual Covenant would have much common ground with them. But I have to be honest and say that this is an issue with me as a person.