Thomas Grantham lived in an age when kings were beheaded, national church structures were dissolved, and Baptists were regularly imprisoned. Grantham was a prolific theologian, a farmer, and a tender shepherd of souls. He staunchly defended Baptist beliefs and heralded universal religious freedom.
Thomas Grantham (1633/34-1692) was born in Hatton, England, a region near Lincolnshire. Like many seventeenth-century figures, his early life is largely unknown. But we do know that he came to faith in Jesus Christ around the age of fifteen . Although his family had been either irreligious or Roman Catholic, he surprisingly joined the General Baptists, being baptized by them in 1653. By 1660, Grantham stood before King Charles II on the General Baptists’ behalf, detailing the harassment, fines, and imprisonment that his fellow Baptists had endured.
Though never formally educated, Grantham’s theological skill is clearly displayed in his most famous work Christianismus Primitivus (1678)—a title that simply means “ancient Christianity.” Over 600 pages in length, it covers everything from believer’s baptism to original sin to a Christian’s involvement in government to instructions on Christian marriage. By briefly exploring Christianismus Primitivus, we can gain a better understanding of what Grantham and late seventeenth-century General Baptists believed. While many important doctrines could be examined, we’ll focus on three. But before that, we’ll consider his importance for today.
A Brief Detour: The Relationship Between General and Free Will Baptists
Grantham was the English General Baptists’ foremost leader in the late seventeenth-century, during which time his Christianismus Primitivus served as the primary text for General Baptist theology. The “General” before Baptist simply means that they believed in a general atonement, or that Christ died for the sins of the whole world. In fact, Free Will Baptists in America were first known as General Baptists, free will being a derogatory descriptor given by Calvinists that American General Baptists embraced and incorporated over time.
When looking at the early General Baptists, modern Free Will Baptists do not simply see people who share a similar theology. Rather, we are exploring the life and thought of our theological ancestors . For non-Free Will Baptists, early English General Baptists such as Helwys, Monck, and Grantham, provide a model for an early advocacy of religious liberty and a rich, instructive, reformed Arminianism. This stated, we can move on to consider Christianismus Primitivus.
Christianity and Tradition
The underlying argument of Christianismus Primitivus is that the Church must model itself after the New Testament, rather than blindly following an inherited tradition, particularly that of the Roman Catholic Church. Grantham thus shows himself to be an inheritor of the Protestant Reformation’s sola scriptura principle (or Scripture as the Church’s supreme guide). Like the Reformers, Grantham rejected Catholicism’s claim that Scripture and tradition were equal authorities. Grantham provocatively wrote, “Cannot the pen of Peter the Apostle, give us as good information in this matter, as the pen of any Pope, pretending to be his successor?”  Clearly, for Grantham, Scripture is the Church’s most reliable guide.
At the same time, tradition has its place and carries a certain level of authority. Grantham regularly quoted the Church Fathers and Church councils when discussing doctrinal matters such as the Godhead. But according to Grantham, a vast difference exists between the Scripture’s authority and tradition’s, notably the source of their authority. As God’s Word, Scripture is an authority in and of itself. Tradition’s authority, on the other hand, is derived from and therefore under Scripture’s authority. Therefore, tradition is only authoritative insofar as it properly interprets and represents Scripture .
Because of Scripture’s supremacy in guiding the Church’s theology and practice, Grantham began Christianismus Primitivus by defending Scripture’s reliability and authority. He begins by positing only three possibilities for the nature of Scripture: (1) The Oracle of God; (2) The Oracle of Satan; or (3) The Device of Men. He concludes that neither option two nor option three are consistent with Scripture, since it condemns both wickedness and the Wicked One, and its teachings concerning morality and justice far surpasses mankind’s common morality and justice. Therefore, Scripture must be the first option, an oracle of God. As such, it is a sufficient guide for all doctrine and practice . The authority of Scripture, then, serves as the basis for all of Grantham’s theology in Christianismus Primitivus. This proves especially true in his discussions of baptism and the church, and original sin and imputed righteousness.
Baptism and the Church
Grantham’s theology of baptism reveals his commitment to the purity of the local church. Unlike Anglicans, Presbyterians, and Catholics, Baptists taught that believers, rather than infants, should be baptized. Grantham was no exception. He insisted that the local church be comprised of genuinely converted members. Therefore, believer’s baptism serves as the gateway to local church membership.
The process would go something like this: a man would repent of his sins, have faith in Christ, receive baptism, and then gain membership in a local church . The logic behind the process was that only genuine believers should be baptized. Furthermore, only baptized believers may be admitted as members of the local church. Grantham explains:
For according to Scripture [sic] rule, all they, and only they, are esteemed of the visible Church, who so far profess repentance from dead works, faith towards God, and the rest of the foundation principles; as thereupon to submit to the ordinance of baptism, as engaging themselves thereby to be no longer the servants of sin, but thence forth the servants of Jesus Christ .
This approach allowed churches to safeguard their doctrine and public witness. More importantly, Grantham was convinced that this method was consistent with the New Testament.
It was no light decision for Grantham or any other Baptist of his day to affirm believer’s baptism and regenerate church membership. Grantham lived in a country with an established church that taught and enforced infant baptism. He was fined, derided, and even imprisoned for his refusal to participate in a church that baptized infants. For Grantham and the English General Baptists, the New Testament did not teach infant baptism. Therefore, they were willing to endure various hardships and deprivations for rejecting it.
Original Sin and Imputed Righteousness
In addition to the themes above, Christianismus Primitivus displays a remarkably reformed understanding of original sin and imputed righteousness. While some so-called Arminians downplayed the effects of original sin and rejected a real imputation of Christ’s righteousness, Grantham did not. He taught that Adam’s sin rendered mankind guilty before God and sinful by nature . Therefore, man is completely depraved. Accordingly, the only possibility of remedying our hopeless state and justifying us before God is Christ’s righteousness imputed to us through faith in Him. Grantham beautifully writes:
Thus when the whole World being found guilty before God, could not, by any righteousness which they have done, lift themselves out of that state of sin and misery; wherefore God, in the greatness of his love to mankind, hath laid help upon One that is mighty to save; who brings near his righteousness, to those that were far from righteousness, that in him they might have righteousness through faith…
For Grantham the glory of salvation resided in the doctrine of double imputation—that glorious exchange where our sin is imputed to Christ, and His righteousness is imputed to us. Grantham writes, “Now certain it is, Christ was made sin for us only by imputation, for he had no sin; and as he was made sin, so we are made the righteousness of God in him, which must needs be by the free imputation of his righteousness to us; for there is otherwise none righteous, no not one” .
These passages make evident that Grantham was neither a semi-Pelagian nor a second-rate theologian. He was an inheritor of the Reformation, and more importantly, a student of Scripture in awe of God’s grace.
Of Christianismus Primitivus, one Grantham scholar writes, “No other General Baptist author of the seventeenth century was able to match the depth and breadth of this work” . As such, this work served as the standard theology for English General Baptists of the late seventeenth- and early eighteenth-century. In fact, this work was even found in the library of Benjamin Laker, a 1680s emigrant from England to Carolina, political leader, prominent farmer, and stepfather-in-law to none other than Paul Palmer, who would found the first known General/Free Will Baptist church in America in 1727 .
Thomas Grantham’s ministry and writings serve as a reminder that biblical doctrine is vitally important to the life of the church. Grantham models an awareness and respect for what God’s people have believed throughout the ages, but he also demonstrates what it means to try everything by Scripture. Grantham’s commitment to Reformation principles and doctrines such as sola Scriptura, imputed righteousness, and original sin defies attempts to write off all Arminians as semi-Pelagians or something worse. As children of the Reformation, General/Free Will Baptists are ultimately a people guided and governed by the Word.
 John Inscore Essick, Thomas Grantham: God’s Messenger from Lincolnshire (Macon, GA: Mercer University Press, 2013), 26.
 For a more detailed discussion of this, see William F. Davidson, The Free Will Baptists in History (Nashville: Randall House Publications, 2001), 3-15; and J. Matthew Pinson, A Free Will Baptist Handbook (Nashville: Randall House Publications, 1998), 1-14.
 Thomas Grantham, Christianismus Primitivus, Or, The Ancient Christian Religion (London: Printed for Francis Smith, 1678), Book IV, 24.
 Bass helpfully explains, “Grantham’s view of tradition did not end in total dismissal. Rather, he cited tradition erratically, depending on his intent either to exploit the difficulties in his opponents’ arguments or to bolster the credibility of his own. Grantham viewed tradition as hopelessly inconsistent, but he was inclined to enlist the support of the Fathers and councils wherever they supplemented his biblical arguments. Scripture remained the sole authority, tradition being valid only derivatively” (Clint C. Bass, Thomas Grantham (1633-1693) and General Baptist Theology (Oxford: Regent’s Park College), 30).
 Christianismus Primitivus, Introduction, Section IV, 5-9.
 For Grantham, the laying on of hands was also an essential part of this process. Since this is a somewhat complex issue amongst late-seventeenth century General Baptists that would require a great deal of explanation, I have chosen to leave it out of the discussion here. For a full discussion, see Bass, 103-136.
 Christianismus Primitivus, Book IV, 176. In this particular quote, Grantham is arguing that baptism is necessary for membership in the universal church. He immediately takes this argument and applies it to membership in the local church.
 Christianismus Prmitivus, Book II, Part I, 77-79.
 Christianismus Prmitivus, Book II, Ch. 3, Sect. VII, 67.
 Ibid., 68. It is commonly accepted by most reformed theologians today that Christ’s righteousness consists of both his active and passive obedience. Grantham also affirms this understanding of Christ’s righteousness. What makes Grantham’s affirmation of this doctrine even more interesting is the fact that the Westminster Assembly was divided over whether or not imputed righteousness consisted of both Christ’s active and passive obedience. See Robert Letham, The Westminster Assembly: Reading Its Theology in Historical Context (Phillipsburg, NJ: P & R Publishing, 2009), 113-114, 253-264.
 Bass, 31.
 Essick, 50; Pinson, 7-8.