[The one fundamental doctrine] which it is forbidden to overthrow, is that we might learn Christ. For Christ is the one and only foundation of the Church.” He is saying that the one final test of a person, or of a church, is that its doctrine must be right concerning Christ. (This, for example, is why all Christians believe the Jehovah Witness movement is not a true church.) Calvin, like Catholic and Orthodox Christians before him, believes everything hinges on this question: “What do you think of Christ?” (Matthew 22:42).
Calvin worked hard to preserve unity in the church. He was conciliatory towards Luther (whom he never actually met) and his followers. The model of his charity can be seen in how he treated Melanchthon, Luther’s principal theologian. Melanchthon was notoriously unstable and held views that Calvin strongly and openly opposed. Within Switzerland Calvin worked with disparate Protestant factions to seek unity as well. In 1549 a union was reached.
Calvin’s correspondence reveals an even deeper concern for true unity. In a letter to Bullinger (Zwingli’s successor and the leader of the German-Swiss Reformed Churches) he says:
What, my dear Bullinger, should more concern us in writing at this time, than to keep up and strengthen brotherly friendship between us by all possible means? We see how much it concerns not our church alone but all Christianity that all to whom the Lord has entrusted any charge in his church should agree in true concord. . . . We must therefore purposefully and carefully cherish association and friendship with all true ministers of Christ . . . in order that the churches to which we minister the Word of God may faithfully agree together. As for me, as far as in me lies, I will always labor to this end.
But there is a rather amazing part of Calvin’s story that I had never heard from those conservative Calvinists who remain steadfastly committed to schism. Following the Council of Trent, which revitalized Roman Catholicism in many excellent ways, Calvin was concerned that the Reformed cause might be lost. In 1557 he tried to persuade Melanchthon to arrange a conference in Germany on behalf of peace and union. In 1560 he made further attempts to renew this project. He proposed an assembly that would renew the union project by “a free and universal council to put an end to the divisions of Christendom.” The very next year, in 1561, he even gave consent to hold a gathering at Poissy which would have included Roman Catholics. He would have attended himself had not his friends prevented it. Adds John Hesselink, “This is all the more remarkable in that his frail body was being wracked by ever more frequent bouts of the painful illness which was to bring him to his death only three years later.”
Many modern conservative Calvinists prefer polemics against other Christians to praying and working for unity. One reason for this stance is that they really do not think other Christians are real Christians. They believe, in other words, what the Reformed minister believes who wrote to his friend and told him he had left the Christian faith by becoming Orthodox. What a sad departure from the true Reformed view of the church.