That all of them may be one, Father, just as you are in me and I am in you. May they also be in us so that the world may believe that you have sent me. (Jesus in Gethsemane on the night in which he was betrayed, from John 17:21)
The Living God
Our help is in the name of the LORD, who made heaven and earth. (Psalm 124:8)I think that Nietzsche must have gotten the idea that God was dead from reading certain theologians. In our study of doctrine, it's easy to speak as if we're discussing a certain type of theory, namely, a theory about a thing which will sit safely on a page and never challenge us, never change us, never take root in us and make us grow. We easily speak as if we study a subject that is mere information and systems. We speak as if our subject were passive rather than living, and rarely speak as if our Subject were more profoundly and deeply alive -- and wiser -- than we are ourselves. In that sense, merely dry theology is bad theology, both blasphemous and harmful to faith. We often behave as if studying our subject did not necessarily change both our minds and our lives; but knowing God necessarily changes both our minds and our lives. If this so-called knowledge of God does not change us, we are dead to God and he to us.
The task of unity looks impossible when we look at human efforts, since no human effort ever has been up to the task of uniting all humanity. Even to discuss Christian unity requires a certain amount of hope, a hope based on the Living God, and on the knowledge that the greatest things happen not by might nor by power but by His Spirit.
The Risen Lord
In him the whole building is joined together and rises to become a Holy Temple in the Lord (Ephesians 2:21)There is no reason for being Christians except for Christ. There is no point in unity for its own sake; it must be for Christ's sake. Neither could we ever rouse ourselves to the necessary levels of humility, kindness, patience, and compassion without Christ. We are, first and foremost, his people. It is in him that the whole building is joined together, in him we are the Temple in which God Lives.
God's Holy People
... built upon prophets and apostles, with Christ Jesus himself the chief cornerstone. (Ephesians 2:20)Scripture compares us to a building -- one whose foundation is already laid: the prophets and the apostles, with Christ Jesus himself as the chief cornerstone. Time and again this analogy is used in Scripture, now Peter calling us a house of living stones built on Christ the cornerstone, now Paul saying that no one can lay a foundation other than the one already laid which is Christ. That is not merely to repeat what was already said: there is no basis for unity other than Christ. It is also to know our limits: we cannot overreach our foundations or we will not be on solid ground. As Scripture makes the comparison by way of image, I'll take an example: In my yard there is a heavy birdbath which at one time was moved off of the small foundation on which it stood. Every heavy rain that birdbath fell over, and kept falling over, until it was returned to its foundation.
If we are built upon prophets and apostles with Christ Jesus himself as the chief cornerstone, then a few things follow. The things that are required of us are the things taught by Christ and his apostles teaching on his authority, which he gave them when he commanded them to make disciples of all nations by baptizing and teaching everything he had made known to them. We cannot take away something which was required by the authority of Christ. Neither do we have the authority to require anything beyond what was required in this way, by Christ and his apostles teaching on his authority. In some places, the church is divided over things that are required; but in too many places it is divided over things that are not. Almost all Christian groups require some belief or other, or some practice or other, in a way which they have no authority to do. Almost all Christian groups teach things that were not received on Christ's authority. Some of these may be acceptable opinions or practices (while others contradict what we've received). But even the acceptable opinions and practices have no business being required in such a way unless they were originally required on Christ's authority. That is not to say that a church, or a church body, or even the Church Universal cannot manage its own affairs; it is to say that our authority managing our own affairs is a very different type of authority than that of Christ, and that confusing the one type of authority with the other is a mistake which has led to a host of unnecessary divisions.
What Are the Essentials?
There are different kinds of essentials. We can look at whether union is possible: the essential there is a living hope that brings action. We can look at methods: the essential things are loving our enemies, praying for those who persecute us, returning good for evil, removing the logs from our own eyes first. The essential tools needed for unity are all in our hands already. We can look at the ground for unity: we are built upon prophets and apostles with Christ Jesus himself as the chief cornerstone. Again, what we need is before us. I don't mean to imply that it's simple; only that it's within our grasp.
If you are offering your gift at the altar and there remember that your brother has something against you, leave your gift at the altar. First go and be reconciled to your brother. Then come and offer your gift. (Matthew 5:23-24)While we're speaking of essential beliefs and practices, here's one: unity itself is an essential. It's been neglected too long.