And he came to Capernaum: and being in the house he asked them, What was it that ye disputed among yourselves by the way? But they held their peace: for by the way they had disputed among themselves, who should be the greatest. And he sat down, and called the twelve, and saith unto them, If any man desire to be first, the same shall be last of all, and servant of all. And he took a child, and set him in the midst of them: and when he had taken him in his arms, he said unto them, Whosoever shall receive one of such children in my name, receiveth me: and whosoever shall receive me, receiveth not me, but him that sent me. And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us. But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me. For he that is not against us is on our part. For whosoever shall give you a cup of water to drink in my name, because ye belong to Christ, verily I say unto you, he shall not lose his reward. And whosoever shall offend one of these little ones that believe in me, it is better for him that a millstone were hanged about his neck, and he were cast into the sea.
- Mark 9:33-42
This passage in the Bible stood out to me. From this, I gather that you don't have to be a part of a particular religious group or denomination to do the work of God or to be part of the body. Jesus regards those who do His will just the same as anyone claiming to believe in structured doctrines and standards. You can either be with God, or against God.