A linguistic breakdown of community is common-unity. There must be something we all have in common that unites us.
It is very important to me that I can trust the people I train with. I can trust that they will give me their best and that if we hurt each other in training, that it was not intentional.
Usually their is some underlying personality trait or goal in common which caused each of us to pick Aikido. I often think we forget to acknowledge and appreciate the sameness and focus too much on the differences in styles and affiliations.