Love for one another through loving and serving the same Lord. While Christians have love for their brothers and sisters, this model does not necessarily entail cooperation among groups of believers. Unity, in other words, applies to the universal or invisible church more than to the visible church. Different denominations entering into formal association or council, retaining their witness to their particular traditions, but collaborating where possible.
Organic unity is the model of Rome.
Spiritual unity is commanded by Christ. Beyond this, unity becomes increasingly problematic. Each person and congregation will have to determine the degree to which closer involvement and cooperative activity are consistent with preservation of their biblical convictions and fulfilment of the task given by the Lord. Of all the peoples of the earth, God has specially set this people apart for himself . Jehovah's exclusive claim on his people is pictured in the story of Hosea's exclusive claim on his unfaithful wife, Gomer.