The Unamended Christadelphians are a "fellowship" within the broader Christadelphian movement worldwide, found only in the United States and Canada. They are, like all Christadelphians, millennialist and non-Trinitarian. The term Unamended Christadelphians is not the formal name of this community but is used informally to identify the grouping since a statement of faith traditionally used by many in this community is the "Unamended Statement of Faith". Similarly, most of the much larger grouping of Amended Christadelphians traditionally use a statement of faith that has been amended and therefore, in North America is known by the prefix "Amended". Nevertheless, Christadelphians worldwide and both Amended and Unamended Christadelphians in North America share fundamentally the same doctrines, with a few exceptions.

The name Christadelphian derives from the Koine Greek meaning “Brethren of Christ”. Like all Christadelphians, The Unamended Christadelphians’ have neither formal, ordained, or paid clergy.

Doctrine In general the following description of doctrine is also true of all Christadelphians worldwide. The particular clauses relating to Christ's "condemned nature" and to the effects of baptism may be more distinctive to traditional Unamended Christadelphian positions in North America, though these are not held by all Unamended Christadelphians.For example Chicago Christadelphians are "Unamended" but their statement contains an amendment: Addendum I – Basis of Belief: "We agree that the Birmingham Unamended Statement of Faith and the Birmingham Amended Statement of Faith represent valid statements of belief subject to the following clarifications regarding the clause that differentiates the two: (1.) From the creation, all mankind has been subject to the Creator and to divine authority. Knowledge and understanding of God’s ways and purpose are directly related to our responsibility to God. (2.) At Christ’s return, all of the baptized, living and dead, will be called to the judgment seat of Christ. In addition, those whom God deems responsible among the unbaptized, living and dead, will be called to judgment. (3.) We reject the teaching that only the baptized in Christ will be raised from the dead for judgment. We also reject the practice of identifying any unbaptized individual as being certain of appearance at the judgment seat." See section below Reunions and Unity Efforts.

The Unamended Christadelphians’ understanding of the nature and person of Jesus Christ, the nature of man, and millennial expectations sets the group apart from the majority of Christian denominations.

Unamended Christadelphians are staunchly non-Trinitarian. The belief that Jesus Christ is not co-equal or co-eternal with but rather subordinate to God the Father is a fundamental doctrine. Furthermore, the Unamended Christadelphians maintain the Holy Spirit is not a distinct member of the Godhead, but the manifestation of God’s power. As such, these doctrines are contrary to the Nicene Creed. The group, while non-Trinitarian, are not adoptionists. The Unamended Christadelphians affirm a belief in the Virgin Birth of Jesus as the literal son of God and Mary.The Christadelphian Statement of Faith: or Doctrines forming the basis of fellowship, also doctrines to be rejected, with the epitome of the commandments of Christ, Christadelphian Advocate Publications: Richmond, VA.

An additional distinguishing feature of doctrine is the teaching on the nature of man, particularly the rejection of a belief in a Platonic immortal soul. Unamended Christadelphians contend the Bible does not teach the soul is an immortal component of mankind. Therefore, the group does not proclaim the afterlife is the soul’s ascension to heaven or descent to eternal punishment in hell. Hell is merely the grave.

In addition to teaching the complete mortality of mankind, Unamended Christadelphians also teach that because of Adam and Eve's disobedience in the Garden of Eden, mankind is inherently sinful and separated from God from birth. Through breaking God's law they created a breach in their relationship with God, and were destined to die. The very nature of mankind was no longer “very good” (Genesis 1), but became unclean in God's sight. Humans inherit this fallen nature from their progenitors, Adam and Eve. By birth, mankind is separated from God. Unamended Christadelphians believe that because Adam and Eve ceased to be very good, their children could not be born very good, or of a nature that is acceptable to God. This understanding is used to explain infant deaths. No person is held personally responsible or guilty for Adam's transgression.

This understanding of the nature of man extends to Jesus Christ, since he was born of a woman. The Unamended teach Jesus, like all mankind, was born into a state separated from God. Despite having a sinful nature as the result of his humanity he did not commit any personal sins, making him the only acceptable sacrifice to atone for the condemned nature of mankind. His sacrificial death (shedding of blood) was necessary to atone for the condemned nature he had like all mankind. He was not a substitute for all men, but a representative, because he also benefited from the redemptive work of his death.

Unamended Christadelphians believe that a correct understanding of God's plan, a life lived in accordance with God's values and Christ's commandments, and baptism into Christ's name are necessary for salvation. By baptism, mankind may also escape their inherited condemnation to death and enter an atoned state, justified before God. Following the New Testament examples, only adult immersions are considered valid baptisms. The Unamended do not baptize infants, or those who do not profess a knowledge of and agree with these outlined doctrinal positions. Furthermore, the Unamended do not preach a doctrine of “once saved always saved”. Faithful service is required after baptism for salvation; however, they widely believe that salvation cannot be earned, but that it is the free gift of God to those children of His that faithfully seek Him, through His son, Jesus Christ.

Since, under Unamended Christadelphian doctrines, the hope of mankind does not depend on an immortal soul, the group proclaims a bodily resurrection of the dead at the literal return of Jesus Christ to the earth. The purpose of resurrection is for judgment of the servants of Jesus Christ. This eschatological interpretation of Biblical prophecy means the Unamended Christadelphians are millennialists. Unamended Christadelphians see the return of Jesus as setting up the literal kingdom of Israel on earth. The kingdom will be worldwide and last for 1,000 years, after which sin and death will be completely eradicated and “God will be all in all.”(1 Corinthians 15:28)

Further distinguishing the Unamended Christadelphians from other Christian denominations is the absence of any church hierarchy or compensated clergy. (See "Organization" below.) The group believes in an inerrancy of the Bible and no other word of modern or ancient times is considered divinely inspired.

Historical development

Foundation The Christadelphian movement developed through the preaching efforts of a British physician, John Thomas (1805–1871). With the death of Thomas in 1871, Christadelphian meetings continued. Since no formal hierarchical structure existed within Christadelphians (see Organization), the death of the founding member was a sad occurrence, but did not result in a collapse of the denomination. Lippy commented this phenomenon was one of the unique features of Christadelphians.Lippy, C.H., "The Christadelphians in North America". Studies in American Religion. Vol. 43. 1989, Lewiston, NY: The Edwin Mellen Press. Each individual meeting continued as an independent unit. Scriptural instruction and cohesion was aided by the work of Roberts in Birmingham, England in the 1860s and in the 1880s Thomas Williams in Chicago, Illinois. Both men traveled to local meetings edifying the brotherhood, and served as editors of The Christadelphian and The Christadelphian Advocate periodicals, respectively.

Statement of Faith & Division of Christadelphian Fellowships

Local statements of faith had been written by local congregations since the 1850s, but formal declarations of faith determining fellowship were not utilized until 1862–1864, the years when Christadelphians began to change from an informal movement into a defined denomination. In America the registration of "groups of believers" and the coining of the name Christadelphian (Ogle County Illinois, 1863) coincided with the British arm of the movement taking a fixed stand against belief in a supernatural devil (Edinburgh, 1863).Hemingray Peter, John Thomas His Friends and His Faith 2003:

The statement of faith (or creed, or confession of faith) used by most Unamended Christadelphians today has its origins in the 1877 statement of faith of the Birmingham Central Ecclesia, Britain (known as the Birmingham Statement of Faith, or BSF). This 1877 statement was partly a response to a doctrinal dispute 1873–1877 between congregations in Britain. The doctrine in dispute was known as “Renunciationism”, “Free life”, or “Turneyism” after the originator Edward Turney of Nottingham. Turney essentially preached Jesus Christ was "not born of a condemned nature" (that is a "free life") and therefore he did not benefit in any way from his own death.Pursell, R., Christadelphians: The Untold Story. 2006. The doctrine was argued against by Robert Roberts in Birmingham and John James Andrew in London among others.

The 1877 BSF already had some informal status as a benchmark in Britain and overseas due to the Birmingham Central Ecclesia being where the editorship of The Christadelphian Magazine was based at the time, but equally local ecclesias usually had their own local statements with similar wording, and continued to do.Wilson, Andrew, History of the Christadelphians 1864–1885: the emergence of a denomination 1997

The 1877 BSF begins with, “A statement of the ‘One Faith,’ upon which the Christadelphian Ecclesia of Birmingham is founded; together with a specification of the fables current in the religious world, of which they require a rejection on the part of all applying for their fellowship.” It contained seventeen provisions outlining the “Truth to be Believed” and seventeen “Fables to be Refused”. This statement of beliefs became basis of fellowship for the majority of Christadelphian meetings in England and North America. Those disagreeing with the Birmingham positions left fellowship. During the next ten years the organization and wording of the statement was revised, but no doctrinal changes were made.Farrar, J.E., Seven Reservations Concerning the Amended Statement of Faith. 1995, Grimsby, ON.

A significant change was the addition of a "Foundation Clause" in 1885 about inspiration. This removed a large part of the British Christadelphian movement into the "Suffolk St." (name of the location of the second major ecclesia in Birmingham) or "Fraternal visitor" (name of the group's magazine) "fellowship". In the same year, March 1885, Thomas Williams commenced publication of The Christadelphian Advocate Magazine in Waterloo, Iowa. Williams supported Birmingham Temperance Hall's addition to BSF 1877 of the new "Foundation Clause", and therefore the "disfellowship" of the Suffolk St. group. Williams also approved Robert's position related to Edward Turney 12 years earlier,Williams, T. Renunciationism. The Christadelphian Advocate.1885(July):p. 104-112. though Turney's Nazarene fellowship had already effectively petered out with his death in 1879 and the return to the main grouping of his supporter David Handley in 1881.