When we ponder unity, we may be considering the uniting of entire denominations with other ones, or entire local congregations with other ones, or simply — most significantly, I think, as an introvert! — the way individual Christians accept and interact with one another.
Churches and denominations may be labeled “inclusive,” which of course implies that other ones are exclusive. Ecumenical churches would tend to be more inclusive, but the exclusive/inclusive dichotomy does not necessarily parallel the ecumenical/non-ecumenical one. Nor does the conservative/liberal contradistinction necessarily predict aspects of unity among believers. It is possible, in other words, to be biblically conservative without being relationally exclusive.
Leroy Garrett wrote recently on the so-called Lunenberg Letter of Alexander Campbell:
It is when differences are allowed to make a people quarrelsome, hateful, and factious and thus exclusive — drawing the line of fellowship — that divisions come. Exclusivism has been the culprit, and when we look for its beginnings in the Movement we find that its roots had been there all along. From the outset Alexander Campbell talked about “uniting the Christians in the sects,” which inferred that he believed there were Christians in the sects, but to some of his followers this appeared to conflict with what he had been saying about baptism by immersion being for the remission of sins.
This gave occasion for the Lunenburg Letter, which became the basis of an ongoing controversy that began in 1837. A lady in Lunenburg, Virginia, one of Campbell’s readers, wrote to him about this apparent contradiction. In view of what he had taught about immersion how could there be Christians in the sects if they have not been immersed, she asked, and sharpened the question by asking him to define a Christian.
After warning against being an “ultraist,” noting that any command can be distorted through overemphasis, and insisting that the devotion of the heart means more than outward forms, Campbell gave the definition the woman asked for: “But who is a Christian? I answer, Every one who believes in his heart that Jesus of Nazareth is the Messiah, the Son of God, repents of his sins, and obeys him in all things according to his measure of knowledge of his will.”
Alexander Campbell’s “Lunenburg letter” is a seminal document in the American Restoration Movement. It shows not only Campbell’s developing thinking, but also his willingness to engage a serious question from someone apparently to his right — a statement about unity in itself! Moreover, Campbell’s definition of “Christian” is worthy of careful thought. One belonging to Christ (= “Christian”), says Campbell, has a personal belief in Jesus, and makes necessary changes in life.
The final phrase in the response–“according to his measure of knowledge of his will”–is of clear significance. It is much easier to be in practical, accepting unity with individuals if we can allow for individual measures of knowledge. In other words, something may be utterly clear to me (and I may or may not be right about it), but if my sister’s or brother’s “measure of knowledge” is different on some point, that matter is better left between that person and God. This principle has come to be known as the “principle of available light.”
Next: a few misc. (finer?) points about unity