John H. Armstrong's 2010 book, Your Church Is Too Small: Why Unity in Christ's Mission Is Vital to the Future of the Church argues that the mission of the church is to participate in the reconciling love of God and that we need to enlarge our hearts in non-sectarian, relational unity and cooperational love, plus have an ecumenical understanding of church.

Since `God is love,' our expressions of love within the Christian community must line up with His. It is His love that enlarges our hearts and forms our character so that we are freed to love others, whether they are a fellow Christian or an enemy.

"Unity" is not synonymous with "unanimity," or "uniformity, but is based in the universally shared reality of all believers: the life of Jesus Christ, through the Holy Spirit, living in us all. The more we are filled with His life, the more we love Him, the more relational unity we will experience with all those who share that same love.

If we have relational unity and cooperational love, we base our conversations and relationships upon our mutual love of God and agreement only on core beliefs, there is immediately space for us to work together for the advancement of the Kingdom of Christ.

One of the chief roadblocks to restoring relational unity in the church today is sectarianism - a path, a way, a method, a party, or a faction. Synonyms would be narrow-minded, parochial, and limited.

Sectarianism implies mutual exclusivity - an exclusivity that thrives where people and groups believe they have a superior claim to truth. Sectarians believe their church/community/tradition can best represent the body of Christ, to the exclusion or minimization of other genuinely Christian groups.

We need not ignore or compromise our beliefs--this would only create a pseudo-unity, but we all need to remember that our beliefs are just our best attempts at understanding Scripture, God, and His message for mankind.

A human knowledge is ultimately provisional - we humans "see through a glass, darkly." The beliefs we assert are, at best, a close approximation to the truth of God. This means that we should always be open to added meaning or nuance ...or even to discovering that we are wrong.

Our understanding of "church" is another roadblock to ecumenism. In truth, any one local congregation is as much the church as any other congregation. Properly understood, the church is the whole of all such congregations throughout the whole earth and it requires that we obey the laws of love (I Corinthians 13).

It is the relational unity of the Church that points people and nations to Christ. The more divided the church, the more impotent it becomes in fulfilling its mission.

The mission of the church is `to participate in the reconciling love of the triune-God who reaches out to a fallen world in Jesus Christ and by the power of the Holy Spirit brings strangers and enemies into God's new and abiding community.

Armstrong believes that "the mission of the church is not to solve society's problems or to gain political influence in order to change culture. And as important as adding members to a church is, recruiting new members for the church is not the church's mission either."

This mission requires that we exemplify God's reconciling love. This doesn't mean that Christians paper over their differences. It means that we have truthful and loving conversations regarding these differences, rather than mouth-to-mouth combat.

Book reviewer Monte E. Wilson (from whom I have borrowed many words in this post) hopefully encourages us that "We can begin a healthy new conversation, a conversation that can lead to reconciliation in a context where the truth is profoundly important. This conversation could well become one of the Holy Spirit's primary ways of pushing forward the `new ecumenism' - an ecumenism rooted in core orthodoxy and deeply shared love for Christ and his mission."