We should take note first, however, that our concern with Christian unity is more than a practical concern to be effective as a force in the world, although it is necessary for such practical reasons also. They must share a common sense of purpose and a commitment to acting together for that purpose. Paul was not different from other leaders when he pleaded that you be united in the same mind and the same purpose. And if a house is divided against itself, that house will not be able to stand. The practicalities are important.
Division does lead to defeat.
And it is true the church today still suffers enormously from its divisions, national, cultural and denominational, especially in its opposition to the powers of darkness. It is clear from our experience in Australia in recent years that the churches have been most effective in bringing questions of social justice into public debate in ways that challenge presently powerful influences when they are expressing common Christian concerns. Unity is strength and disunity is destructive. Even if it were not of any immediate practical advantage, we could not be true to Christ if we were not committed to show in our lives together in the fellowship that hope for unity of all things that was the purpose of his coming into the world. We cannot truthfully witness to the reconciliation of people with God through the work of Christ unless we are also reconciled to one another.