At the Lord's Supper, Christians eat and drink together. We call it communion because by it we are unified in Christ. This togetherness—this community—is central to the life of the Church. Its distinguishing feature is not multiplicity, but oneness: "There is one body and one Spirit—just as you were called to the one hope that belongs to your call—one Lord, one faith, one baptism, one God and Father of all, who is over all and through all and in all" (Eph. 4:4-6). Like all good stories there is unity to the story of the Church. It looks much different now than it did in the first century, but it's still the same Church. Part of its life is this story: where did it come from, who keeps it together, where is it going? While there are all kinds of interesting particulars, there is really only one answer to these questions: Christ. He is the founder of the Church, He is its sustainer, and He is the goal toward which it is progressing. History will cumlminate in the absolute glorification of Christ before all creation, and the Church's primary task is to prepare the way for Him. The Church is healthiest when Christians are most dedicated to this task. This doesn't mean the death of denominations, it simply means they will be working humbly together. Just as the men of Israel worked together to rebuild the wall around Jerusalem (Neh. 3), so all Christians regardless of denomination must build the kingdom together.
To be successful the Church must be healthy internally. Its worship must reflect the standards and guidelines found in the Bible, and its observance of the sacraments cannot be taken lightly or neglected. The Church is to be the one consistently safe place for Christians in a mostly hostile world. This is not to imply the Church is a location or building but that it is a spiritual presence providing refuge for the people of God. The apostle John made it plain how the Church is to hold itself together. The world will know us by our love, he said. "Dear friends, since God so loved us, we also ought to love one another" (1 John 4:11). The Church is at its best when it is filled with the selfless love of Christ and is sharing that love with the world.
It is the Church's responsibility to spread the kingdom Christ set up during His lifetime. This kingdom is spiritual and its citizenry is increased whenever someone is baptized in the name of the Father, Son and Holy Spirit, but it exists in a physical world and will lead to the transformation of all civilization and culture. While this goal often seems hopeless and beyond reach, God has promised that the Church will triumph:
"On this rock I will build my church, and the gates of hell shall not prevail against it." — Matthew 16:18