One of the great griefs here in this vale of tears is that God’s people—those blood-bought brothers and sisters who will spend eternity with the Saints and with their heavenly Lord with whom they have union—cannot get along. Sometimes, the issues are major—the nature of gospel preaching, for instance. Sometimes, they are minor—I think some of the divisions over worship today fall into this category. I dare not say all, for worship is an important matter. What shall be our attitude to all of this? I can recommend none better than that of John Calvin, that lover of church unity, who feared to leave Rome lest he was engaging in schism! When Martin Luther was “flaming against the Zurichers,” Calvin said the division between Luther and the Zwinglians of Zurich caused him “no little grief” and he “lamented in [his] own breast in silence.”
Sometimes separation must take place—but it must be deeply lamented and all done to secure unity before such a step taken.
 Second Defence of the Pious and Orthodox Faith Concerning the Sacraments, in answer to the Calumnies of Joachim Westphal [Tracts, trans. Henry Beveridge (Edinburgh: Calvin Translation Society, 1859), 2:253].