"Unity in diversity" is decried as heretical by many preachers in "the church", a species of treason against the arrangement of GOD. They seem to think that such a thing is impossible, that unity can only come through conformity; every one else must come to our understanding for there to be unity.
However, the Christ himself is the proof that such a thing is not only possible, but required: "For He Himself is our peace, who made both groups into one, and broke down the barrier of the dividing wall..." (Ephesians 2:13-22). Read the passage for yourself, and note well that the ancient and formidable hostility between Jew and Gentile was of much more consequence than any which exists between purported Christians. And yet, they have been reconciled into one body. Note the word "reconciled", for it is a key word. To reconcile is not to make identical, but to bring together in spite of differences. Jew and Gentile were not merged into a new person; they remained Jew and Gentile as they had been. Husband and wife do not become a new person, they remain as they were before marriage. In both cases, the parties are reconciled to each other; they are together in spite of differences. The difference between the former state of disunity and the new state of unity is not one of conformity, but of tolerance of differences because of love. Note very well also that neither Jew nor Gentile has achieved this state of unity. It is He (the Lord Jesus Christ) who has brought about this state of oneness. Our function is not to cause such unity, but to accept it and live in it, to preserve it in the bond of peace. Peace is not served by perpetual wrangling over doctrinal details, but acceptance of our brother as is, because he is our brother. I love my physical brother in spite of our differences, even our doctrinal (or spiritual) differences. He is still my brother both physically and spiritually, even though we are not identical. We are both children of the same father, both physically and spiritually.
Why do we feel compelled to isolate ourselves from our spiritual brothers? Can we not apply the same quality of love (or even higher) to our spiritual brothers as we do to our physical brothers? As the Lord said: "By this shall all men know that you are my disciples, if you have love for one another." If love exists, all other differences can be reconciled.
Our own country is a working example of unity in diversity. Like the people of GOD, it depends on the tolerance of the individual for those who are different; like the people of GOD, its peace is threatened when differences are emphasized, instead of likenesses. The principle is the same, because only those who are reconciled can withstand the differences. Until black and white learn to tolerate their differences, until animosities between Hispanic and "gringo" can be reduced, until Irish and English learn to live with each other, there will continue to be clashes because of differences. Tolerance and reconciliation depend on love, the recognition that all are brothers, in spite of differences. This is true both spiritually and physically.