I'm honestly in awe about this particular scripture (and honestly I can't keep thanking jwfacts enough for providing biblical contradictions to the jw doctrine!)
"John said to him: "Teacher, we saw a certain man expelling demons by the use of your name and we tried to prevent him, because he was not accompanying us." But Jesus said: "Do not try to prevent him, for there is no one that will do a powerful work on the basis of my name that will quickly be able to revile me; for he that is not against us is for us. For whoever gives YOU a cup of water to drink on the ground that YOU belong to Christ, I truly tell YOU, he will by no means lose his reward. But whoever stumbles one of these little ones that believe, it would be finer for him if a millstone such as is turned by an ass were put around his neck and he were actually pitched into the sea." Mark 9:38-42
To me this really is a clear as day statement from Jesus that we need not be part of any organization, I do know that in my Congregations we were given the whole "don't try to stumble one another" speech, but looking at it in full, taking a step back and reading the context - he (in my opinion I suppose!) clearly means not to stumble one another on the basis of whether or not we are a part of this church or that church, we are all his followers!
honestly im learning more about jesus and actual scriptures as a whole NOW then i ever did as a kid in the kingdom hall