The event usually taken to be the starter’s gun of the Reformation was Martin Luther’s Ninety-Five Theses, which he nailed to the church door in Wittemburg in 1517. Hard on the heels of Lutheran reforms of the German church came movements under Zwingli and Calvin in Switzerland. In 1534, under Henry VIII, England broke with Rome and by the time of Elizabeth’s reign England had its own Protestant confession. In the space of a few decades, the map of Europe had been redrawn in recognition of new Protestant nation states. Roman Catholic Christendom was no longer universal. The seeds of the Reformation were sown with the rediscovery of ancient texts and the new learning of the Renaissance, with the Biblical humanist movement and the early reformers such as Wycliffe, Tyndale and Hus who believed the Scriptures should be available to every person in their own language.
The central question of the Reformation was that of authority. Where did authority for religious belief and practice lie? For the past millennium the answer had been, “with the Holy Roman Church of course,” under the Popes who traced their line of succession back to Peter. But the late medieval Catholic church was a spiritual wreck; plagued by immorality, power struggles, huge divides between rich and poor, between clergy and laity, and corruption at every level. And, what became more and more evident as men turned again to the original Scriptures, a huge divergence of doctrine from what the Bible taught. The common ground of the Protestant reformers was reliance on Sola Scriptura — Scripture alone — as the authority for faith, doctrine and Christian life. Salvation was recognised to come by grace alone, through faith alone in Christ alone, not through the Roman Catholic priesthood and sacramental system. On these elements the Reformers agreed. Where they disagreed most vehemently was on doctrines related to church government and sacraments.
The so-called “Radical Reformation” sought to take reformation beyond that of the magisterial reformers such as Luther, Zwingli and Calvin and their state churches. Among these radical reformers were three broad groups; the Anabaptists, the Spiritualists and the Evangelical Rationalists. The Spiritualists held that ultimate authority lay with the influence of the Holy Spirit, the Rationalists identified human reason as the ultimate authority and the Anabaptists stuck with Scripture alone. The Rationalists gave rise to the Deists and Unitarian movement, the Spiritualists were the forerunners of the Quakers and similar groups, and the Anabaptists were distinctive in their separation form the world and their view of the church as a community of gathered, confessing believers, rather than a state institution into which one was born.
How did the doctrine of the Triune God stand up to the new scrutiny of Sola Scriptura during the Reformation? Reformers such as Luther and Calvin were not shy when it came to challenging doctrines they believed were unscriptural. Had they believed the doctrine of the Trinity to be incompatible with Bible teaching, doubtless they would have abandoned or modified it accordingly. But they held to it; not because they were wedded to church tradition, but because they found it in Scripture. They threw out the whole basis of salvation as propounded by medieval Roman Catholicism, so it hardly seems likely they would have baulked at discarding the church’s doctrine of the Godhead had it been found wanting. They did not see the Trinity as a fabrication of the church but as a scriptural doctrine. The Augsburg Confession of the Lutheran church, Calvin’s Institutes of the Christian Religion, the reformed Westminster Confession of Faith and the Anglican Thirty-Nine Articles all uphold the Trinity as a doctrine “proved by most certain warrants of Holy Scripture.”
Of course, this acceptance of the Trinity by the Protestant reformers does not of itself validate the doctrine; only Scripture can do that. Nor does the majority position of itself guarantee truth. But it’s important to understand Protestant doctrines in the context of the sweeping, Bible-based reforms occurring at the time. Christadelphian writer Robert Roberts dismissed the Reformers’ discernment when he wrote:
Was it likely the Reformers should at once, and in every particular, emancipate themselves from the spiritual bondage of Romish tradition? …Was it not more likely that their achievements in the matter would be only partial, and that their new-born Reformation would be swaddled with many of the rags and tatters of the apostate church against which they rebelled? … so far as doctrinal rectification was concerned, a very small part of the truth was brought to light, and many of the greatest heresies of the church of Rome were retained and still continue to be the groundwork of the Protestant church.” 
Roberts of course believed that Christadelphians have succeeded where the Reformers failed, not through any special inspiration, but essentially because the Reformers continued old habits of the apostate church and didn’t study the Scripture as much as Roberts and his mentor John Thomas did. I suspect that many (but by no means all) Christadelphians today would be privately uncomfortable with Roberts’ assertions, even though it remains their denomination’s official position. Apart from the naivety or arrogance which might underlie Roberts’ statements, he has made a fundamental error in his most basic assumption. He is arguing like a Rationalist, putting human reason to the fore and making the discernment of truth a matter of who had the better brain. He does not acknowledge that the Reformers’ reverence for the authority of Scripture, as opposed to the authority of the Roman Church, was the very basis for their doctrinal discernment. He gives them no credit for their exegetical or theological abilities. Nor does Roberts allow any room for the guiding hand of God’s Providence or the influence of his Spirit in any of this. For him it is all about brainpower, and because Christadelphian “reasoning” finds different answers in the Bible than the Reformers’ “reasoning,” he effectively accuses the latter of a combination of inferior reasoning and a continued indebtedness to the legacy of the Roman Church’s “authority.” This is a grave mistake.
If the doctrine of the Trinity is held to be Scriptural then it is not based on Papal authority. Unfortunately, a number of Christadelphian writers either state or imply that Trinitarian doctrine is a product of the Roman Catholic church, not understanding the long history of elucidation of the principles of the doctrine from apostolic times. More recently, James Andrews has also challenged the integrity of the Reformers with his statement, “It was therefore perhaps inevitable that the Protestant reformers were limited in the extent to which they were willing or able to challenge such fundamental teachings as the doctrine of the Trinity,”  which makes it sound like the Reformers wanted to reject the Trinity but were too scared!! Noting the fearless vigour with which the likes of Calvin and Luther oppose Roman Catholic dogma and practice, and how staunchly they defend the Trinity from Scripture, makes one wonder how Andrews could suggest this.
Nevertheless, it is true that not all Bible scholars during the Reformation period accepted the Trinity as scriptural. Non-trinitarian groups such as Christadelphians are quick to point to these minority voices to support their own positions. Being able to say, “see, we aren’t the only ones who disagree,” seems to give some reassurance or validation to any non-mainstream position. But it is equally invalid to determine that the minority (persecuted or not) is likely to be right as it is to assume the majority position is, purely on that basis. “It is a matter of great encouragement to us, whose religious views are regarded as unorthodox by our contemporaries,” says Christadelphian Fred Pearce, “to find that in a number of cases where major doctrines are concerned, these early believers had come to the same conclusions as ourselves. And how should it be otherwise, for we have sought to do what they did — go back to the Scriptures alone in our search for truth.”  Alas, this is just another, politer, version of Roberts’ assertion that only those who have reached similar conclusions as the Christadelphians have really read the Scriptures correctly.
The examples of two non-trinitarians of the Reformation era will serve to demonstrate that rejection of the orthodox doctrine of the Trinity did not mean their views were uniform across the spectrum of “major” doctrines. In fact, I doubt that there would be enough common ground for Christadelphians to be “in fellowship” with them, and these men would not have accepted all of the 30 articles of the Christadelphian Statement of Faith, nor eschewed the same 35 Doctrines to Be Rejected as Christadelphians are obliged to do today. Just as Christadelphianism is unlike any of the ancient heresies, so it has minimal common ground with the non-orthodox ideas of the Reformation era. Christadelphianism is unique and Christadelphians should be cautious as to who they nominate as predecessors or kindred, and for what reason.
Michael Servetus (1511–1553) was a very accomplished man with a breadth of learning that encompassed theology, medicine, astronomy, geography, meteorology, poetry and proficiency in several languages. He was condemned as a heretic by both Catholics and Protestants for his non-trinitarian views and burnt at the stake in Geneva. He is revered today for his medical insights and as a martyr to the cause of freedom of religious belief. Servetus’ major writings against the Trinity were On the Errors of the Trinity, Dialogues on the Trinity and Christianismi Restitutio, which covered a number of aspects of the church that required “restitution.” However, Servetus was not strictly anti-trinitarian in that he did not deny the divinity of Christ. His views resemble modalistic monarchianism in his effort to refute what he saw as the “tritheism” of Nicene theology. He saw God as the source of emanations or intermediaries such as reason, wisdom, and Word (logos) which generate reality. God has in himself the being or essence of his creation, conferring the essence to everything that exists and filling everything. All things in the world emanate from God through the divine Word and the emanations of God participate to different degrees in his essence. He therefore saw no real distinction between the persons of the Trinity; they were not persons but modes of divine manifestation. The Logos preexisted with the Father and became man, his flesh being the substance and Jesus Christ the combination. Servetus did not view the Holy Spirit as a person. Christ is the intermediary who allows mankind to approach God and rise up to God. Blending his theology and medicine, Servetus believed the soul of man was in the blood and in studying the circulation of the blood he believed he was studying the soul.
Faustus Socinus (1539-1604) was the originator of Socinianism, which is arguably the closest historical precedent for Christadelphianism. John Thomas denied that Christadelphians were Socinians, but more recently some writers have sought to highlight the similarities between the two belief systems, at least in terms of anti-trinitarianism. Socinius’ views are set out in the Racovian Catechism, a long work which reads partly as a catechism but also partly as a series of answers to “wrested scriptures,” such as the passages typically used to support Trinitarian theology. The counter-arguments to passages used to support or explain the Trinity are not necessarily those used by Christadelphians, however. The Catechism upholds God as one in essence and person; the Father of the Lord Jesus Christ. The Socinian view of the nature of Christ is very similar to that of Christadelphians; the Catechism denies the pre-existence and intrinsic divinity of Christ but upholds the virgin birth. Christ is described as a man. Other points of general agreement with Christadelphians are a rejection of propitiatory atonement, rejection of the personhood of the Holy Spirit, and a position of conscientious objection. Nevertheless there are some key differences. The Racovian Catechism states that Jesus ascended to heaven to obtain the teachings of the Father, and was subsequently sent “down from heaven” to proclaim these things, being endowed with the Holy Spirit (John 3:13). In this sense he had “seen the Father.” The will of God declared by Christ consists of the New Covenant, which is defined as a series of moral precepts as given through Moses, the prophets, Christ and the apostles. The prayer for God’s kingdom to come is interpreted as “God would cause all men to acknowledge his jurisdiction and sovereignty over them, as their creator, and to submit themselves to his rule
and authority.” The assistance of the Holy Spirit in believers today is seen as real and essential. The devil is the “author and active promoter of temptations” and there are bad angels as well as good. Christ is to be worshipped and addressed in prayer. Baptism is not essential. Socinian teachings were the basis of belief of the Polish Brethren and the Transylvanian Unitarians and have been very influential on the various flavours of Unitarianism since.
Christadelphians are rightly interested in the history of their denomination and their beliefs. Their doctrine set is highly integrated and consistent within itself, and it is unique; either unique and true, or unique and false. Either way, an appeal to predecessors is irrelevant because the common ground is only partial. Christadelphians would be the first to insist that Scripture alone should be the litmus test. Here we confront the dilemma that in the history of Christianity, no other group (even non-trinitarians) has held the same combination of doctrines, including some of the bravest, most gifted and most independent-thinking Bible scholars. The inevitable conclusion is that either no one else sought the Truth as sincerely and objectively as John Thomas and his followers did, or that everyone else who tried just didn’t make the grade.
1. Robert Roberts, Christendom Astray from the Bible. (1884, repr. West Beach SA: Logos Publications, 1984) 23.
2. James Andrews, “Biblical Monotheism in the Radical Reformation,” in Thomas E. Gaston, ed. One God, The Father (East Boldon UK: Willow, 2013), 167.
3. F.T.P., in Alan Eyre, The Protesters. (Birmingham: The Christadelphian, 1975), preface.
4. See the detailed and interesting blog, “Are Christadelphians Unitarian, Socinian, or something else?” at http://blog.dianoigo.com/