Atheist and Agnostic being separate is a slight mistake. Gnostic and agnostic has to do with certainty. Theist and atheist has to do with belief. A person who is certain there is a god is a gnostic theist. A person who isn't sure but thinks there is a god is an agnostic theist. I am an agnostic atheist in that I do not believe in any gods, but I have no way to be certain. Some atheists are positive there are no gods, they are gnostic atheists.
My denomination is Baptist, although that means little more than a part of the name of a family I belong to. How can you be a thinking person living and growing in your walk with christ and really focus on all the minutiae of the distinctions among the faiths? How can you possibly agree with everything officially held by your denomination? My biological family is no more perfect than my church family, but they are both wonderful and encouraging even with their faults.
I don't put much stock into people making the case against organized religion. Some people are turned off by "Religion" and the churches often cater to that view. I think it is a mistake to avoid the "Religion/Religous" label just to be "Accepted" by those that will find you "Unacceptable" even with your efforts to appease them.