Fellowship is a funny word. Understandably we throw it around an awful lot. We intend it to mean something like sharing time or hanging out. John's emphasis for his community to remain in fellowship is brought through relationship. A vertical relationship with God and a horizontal relationship with one another. In John's discription of this fellowship (or koinonia) the life of God comes through in the life of the community. As we will soon see, this life (given thru the Holy Spirit living in us) is a life of love, love for God and love for one another. This is the vision of true fellowship, koinonia, living in life with one another, expressing the life God has given thru God's son.
This is the essence of what it means to be the church in the world. If the world peaked into the lives of our communities how would they see the love of God and each other expressed? (obedience comes through our identity as God's children, telling of our Father who loves us). What does this look like in your household?