Tensions were high in the elector states of Germany. At the Second Diet of Speyer in April 1529, elector princes loyal to Martin Luther’s insights issued a protest, a document that would give them the name “Protestants.” Philip of Hesse, the landgrave who was one of the leaders of this emerging Protestant movement, desired a single confessional statement that would link German evangelicals together against Charles V, the Holy Roman Emperor, and his Roman Catholic allies.

However, there was a significant barrier in the way: the nature of Christ’s presence in the Lord’s Supper. In order to work toward unity, Philip gathered key evangelical theologians to Marburg, a city in the territory he oversaw as landgrave. In addition to Luther, Philip Melanchthon, Martin Bucer from Strasbourg, and Huldrych Zwingli from Zurich were also present.

In October 1529, as the theologians debated among themselves before engaging in public debates before the landgrave, it became clear that there were two sides: the Lutherans, who generally followed Luther’s insistence that “this is my body” meant some sort of corporal presence, and the Reformed, who sided with Zwingli’s claim that Jesus’ words required a symbolic understanding. Shuttling between the two sides, working for the unity of the church, was Martin Bucer. It was a role that he was well-suited to play.

The Formation of a Mediator

Bucer was born in Selestat, near Strasbourg, in 1491. Though his father was a shoemaker, he received a solid education at the Latin school in his town and entered the Dominican monastery there at the age of 15. His order eventually sent him to Heidelberg to receive further training. It was a fateful trip: not only was he exposed to the work of Erasmus, committing him to a humanist interest in the biblical text, but he was present for Luther’s 1518 Heidelberg Disputation. As he heard Luther unpack the differences between the theology of glory — that relied upon the law for right standing with God — and the theology of the cross — that relied upon Jesus alone for salvation — Bucer began to wrestle with the gospel in its pure and recovered form.

Something happens in the Lord’s Supper — Jesus is present in feeding his people with food for the spiritual journey.By 1521, Bucer had committed himself to Luther’s reformational understanding of the gospel. He left Heidelberg and began to pastor a parish in Landstuhl. He embraced the further reform of clerical marriage in 1523, marrying Elizabeth Silbereisen, a former nun. However, his patron’s political and military failures forced him to leave his parish; Bucer had decided to flee to Wittenberg. In order to protect his wife, he took her to relatives in Strasbourg. Bucer himself never made it to Wittenberg; at the urging of the Strasbourg city council, he took the parish of St. Aurelia in 1524 and, seven years later, the parish of St. Thomas.

Though Bucer never wavered from the insights on sola fide that he gained from Luther, by the time he made it to Strasbourg, he raised questions about Luther’s teaching on the Lord’s Supper. His friendship with Zwingli and Andreas Carlstadt caused him to listen to their concerns about the downstream effects of Luther’s doctrine of ubiquity (the idea that the physical body of Jesus is omnipresent) on Christological belief. In addition, Zwingli argued that if Jesus’ resurrection body is a real body and it is present at the right hand of God the Father, then surely it cannot be “everywhere.”

And yet, Bucer also believed that Luther had some important points, too. Something happens in the Lord’s Supper — Jesus is present in feeding his people with food for the spiritual journey. There is an objective reality in the Supper, an objective reality that grounds our subjective response. As believers eat the Supper by faith, they actually gain spiritual benefit. Luther was right about that, Bucer held.

Failure and Success in the Work

Thus, Bucer was the right person to mediate between the two sides, to work for the unity of the church. As the theologians gathered at Marburg in 1529 and debated privately, they worked in pairs: Melanchthon discussed with Zwingli, Luther with the Reformed theologian Johannes Oecolampadius. Bucer worked in the background, trying to get the sides to come to an agreement. None of this work was easy because the two sides were fairly entrenched. In one of Luther’s first speeches, he declared: “I am prepared, then, to take part in a debate. Not as if I were desirous of changing my conviction, which, on the contrary, is absolutely firm. Still, I want to present the foundation of my faith and show where others err.” In a similar fashion, Zwingli would get frustrated with Luther, at one point declaring that John 6:63 was a verse that would break his neck.

In the end, neither side would back down. The final document that was published, the Marburg Articles, declared that “although we have not at this time agreed whether the true body and blood of Christ are bodily in the bread and wine, each side is able to display Christian love to the other (as far as conscience allows).” And so, perhaps Bucer’s work for the unity of the church was a failure at this point.

Yet Bucer did not stop working for the church’s unity. The following year, he crafted the Tetrapolitan Confession as a middle way between the Lutheran and Reformed positions. In it, he provided his mediating position on the Lord’s Supper: that in the Supper, Christ “deigns to give his true body and true blood to be eaten and drunk for the food and drink of souls,” and that any further contention and inquiry into how that happens is “superfluous” and unprofitable. And yet, with a nod toward Zwingli, Bucer also taught that “we who partake of one bread in the holy Supper may be among ourselves one bread and one body.”

Because he was able to find a middle ground between Luther and Zwingli, he urged Strasbourg to subscribe to the Augsburg Confession in 1532 and came to an agreement with Luther and Melanchthon in the Wittenberg Concord in 1536. In that document, the theologians agreed that the body of Christ is in heaven at the right hand of the Father, even as the Supper is a true means of grace to the one who receives it by faith. Even though several of the Zurich theologians failed to adopt the concord, Bucer did not stop working for the unity of the church.

A Life Toward Unity

Bucer’s testimony and example still live on as one who believed in and worked for the unity of Christ’s church.This determination to work with others to seek the unity of Christ’s church would continue to typify Bucer’s ministry until the end of his life. Famously, in 1539, he took in the apparently failed Reformer, John Calvin, and gave him a place of ministry in Strasbourg — one that proved instrumental in Calvin’s future return to ministry in Geneva. He engaged in various conferences with Lutherans and Catholics at Hagenau, Worms, and Regensburg in 1540-41, trying to find a middle way toward further reforms in these cities. When Peter Martyr Vermigli fled Italy, having embraced the Reformation, Bucer called him to Strasbourg so that he might teach theology in the city’s academy.

Even when Bucer was finally forced to leave Strasbourg in 1549, he went to England to assist the Archbishop of Canterbury, Thomas Cranmer, in trying to craft unifying solutions to divisive issues. In the revision of the Book of Common Prayer produced in 1552, Bucer’s influence was seen in mediating language, especially in the rubrics for baptism and the Lord’s Supper, and in the ongoing use of vestments. Bucer would not see this new prayer book. He died in England in 1551, buried at Great St. Mary’s Church in Cambridge. But Bucer’s testimony and example still live on as one who believed in and worked for the unity of Christ’s church.

Pieter Saenredam, “Interior of St. Bavo, Haarlem,” oil on canvas, 15.2” x 18.7”, 1628.