The WTS is very vague about who passed the torch from 100 AD to 1879 AD presumably to Russell.
Was there an organization?
Were their individuals...if so, who were they? How can they be identified out of the various Christian groups during that time, Roman Catholics, Orthodox Church, Coptic Christians, and various Protestant groups?
***w60 7/15 p. 435 The Awake "Faithful and Discreet Slave"*** Down through the years the slavelike congregation has been feeding its true members faithfully and discreetly. From Pentecost, A.D. 33, up to this very present hour this has been lovingly and carefully performed. Yes, and these "domestics" have been fed on progressive spiritual food that keeps them abreast of the "bright light that is getting lighter and lighter until the day is firmly established." (Prov. 4:18) All this has proved to be "food at the proper time," as stated by Jesus. Jesus confidently answers that question in the above-referred-to illustration of the sower by saying: "Just as the weeds are collected and burned with fire, so it will be in the consummation of the system of things. At that time the righteous ones will shine as brightly as the sun in the kingdom of their Father." (Matt. 13:40, 43) So it was indicated that many of the "wheat" class of righteous ones, anointed ones, would survive here on earth up to and during the "time of the end."
----------------------
In the past the Watchtower has downplayed or eliminated certain groups as possible members of the FDS between 100 and 1879 AD.
w63 3/1 p.145 The General Priesthood Todayw65 3/15 pp. 191-192 Questions from Readers (excerpts)
That Jehovah has also had witnesses on earth from Christ’s time until our day seems to be indicated by Jesus’ parable of the wheat and weeds
This parable may be taken to imply that during all this time, from the first sowing until the harvest, there would be some genuineChristians, "wheat," even though at times their number might be exceedingly small.
Thus throughout the centuries there have been professed Christians who rejected the error of the trinity, usually called
There were those who closely
followed primitive Christianity and who were known as quartodeciman
s because of celebrating Christ’s memorial on Nisan 14, holding out against the paganizing trend of Rome. Then there were the
Paulicans from the seventh century onward, whose teachings have been termed "genuine apostolic Bible-Christianity." They stood solely by the "New Testament," practiced adult baptism, believed that God in his love had sent an angel to earth who at his baptism became God’s Son. They rejected unscriptural tradition, had no clergy-laity distinction, refused to revere the cross.
Then there were the
WaldensesWaldenses
from the twelfth century forward, who had much in common with the previous Paulicians in rejecting all false tradition such as purgatory, the mass, and so forth, and adhering closely to the Bible, although they did not limit themselves to the so-called "New Testament." The only two ceremonies they recognized were baptism and the Lord’s evening meal. They strictly followed Bible principles regarding morality and refused to celebrate popular religious holidays such as Palm Sunday, Easter, All Saints’ Day, and so forth. Typical is the statement of one of them, who was martyred, that ‘the Cross should not be prayed to but loathed as the instrument of the Just One’s death.’
Many were the Arians, Paulicians and Waldenses, not to mention others, who because of their Bible-based religion suffered martyrdom.
Not that this in itself or together with their beliefs, as noted in the foregoing, indicated that all of them had God’s approval. Why not? Because time and again not a few of these took up the sword to defend themselves against Roman Catholic crusades in violation of Matthew 26:52.
w75 10/1 p. 583 Almost 6,000 Years of Witnessing for Jehovah
But after the close of the first century, as foretold, the "weed" class of false Christians, sown by Satan, began to persecute the "wheat" class, the true Christians. About the fourth century, some who rejected the pagan Trinity doctrine were labeled "Arians." Others who held faithfully to celebrating the Memorial of Christ’s death on Nisan 14 were termed "Quartodecimans (or, Fourteenthers)." In the seventh century some who held to "genuine apostolic Bible-Christianity" were called "Paulicians." But this name-calling, along with persecutions, did not deter faithful anointed Christians from keeping their integrity!—Luke chapters 1 and 2; Matt. 13:24-30.
Amidst Christendom’s vast domain of imitation Christians, the true anointed Christians continued to remain loyal in the face of sadistic tortures and martyrdom at the hands of the Catholic priesthood. From the twelfth century C.E., the "Waldenses" in France rejected Catholic traditions in favor of adhering closely to the Bible. Many of these became martyrs. One of them said: ‘The Cross should not be prayed to but loathed as the instrument of the Just One’s death.’
w81 8/1 p.15 TheWaldenses—Heretics or Truth-Seekers?
But the early Waldenses, although accused of being "heretics," were in fact sincere truth-seekers and pioneers in Bible translation, Bible teaching and simple Christian living. To be sure, they did not break free from all the false doctrines of Babylonish false religion. But they apparently lived up to the knowledge they had of God’s Word. Many, it would appear, were willing to die rather than renounce their faith. Of course, only "Jehovah knows those who belong to him." We can, therefore, safely leave any reward of future life in his hands.—2 Tim. 2:19.
Revelation Climax book (1988) chap. 6 p. 31 Unlocking a Sacred Secret
In his parable of the wheat and the weeds, Jesus foretold the time of darkness that would exist while Christendom reigned supreme. Nevertheless, through all the centuries of apostasy, there would exist individual wheatlike Christians, genuine anointed ones. (Matthew 13:24-29, 36-43)
Revelation Climax book (1988) chap. 11 p.57 Is Your Name in the Book of Life?
Likewise, when professed Christians were absorbed into Babylon the Great, the world empire of false religion, during the long centuries of the great apostasy, there must always have been a few individuals who tried, against great odds, to do Jehovah’s will. These were righteous like wheat hidden amid a profusion of sectarian weeds.—Revelation 17:3-6; Matthew 13:24-29.
---------------------------and here's another "guess"
*** (Proclaimers) jv chap. 5 p. 44 Proclaiming the Lord’s Return (1870-1914) ***But what about “the wheat”? Who were among “the sons of the kingdom” during the centuries-long apostasy? We cannot say for a certainty. The literal weeds of Jesus’ illustration are generally considered to be bearded darnel, which very much resembles wheat until maturity, when it can readily be distinguished from wheat by its smaller black seeds. Similarly, only at “the harvest” would a clear distinction be made between imitation Christians and the true “sons of the kingdom.” Nevertheless, Jesus said: “Let both grow together until the harvest.” True Christianity, then, was never completely stamped out.
Throughout the centuries there have always been truth lovers. To mention just a few: John Wycliffe (c. 1330-1384) and William Tyndale (c. 1494-1536) furthered the work of Bible translation even at the risk of their life or freedom. Wolfgang Fabricius Capito (1478-1541), Martin Cellarius (1499-1564), Johannes Campanus (c. 1500-1575), and Thomas Emlyn (1663-c. 1741) accepted the Bible as God’s Word and rejected the Trinity. Henry Grew (1781-1862) and George Storrs (1796-1879) not only accepted the Bible and rejected the Trinity but also expressed appreciation for the ransom sacrifice of Christ.
-------------------------
Jehovah’s Witnesses believe that this parable pertains to the
one true congregation of Jesus Christ’s anointed followers. Beginning
with Pentecost, 33 C.E., and continuing through the 19 centuries
since then, this slavelike congregation has been feeding its members
spiritually, doing so faithfully and discreetly. (WT 1981 March
1, p. 24)
http://www.watchtowerinformationservice.org/doctrine-changes/myth-of-the-faithful-and-discreet-slave/
as recorded at Matthew chapter thirteen. Therein Jesus stated that both the wheat and the weeds would continue growing together until the harvest, when a separation would take place.
"Arians."Already such pre-Reformation movements as the Waldenses in Central Europe and the Lollards of Britain had tried to live up to the general priesthood. After the "reformation" a movement in Germany known as "Pietism" and our generation’s Oxford movement have to some extent tried to do the same, but all these efforts were evidently without the support of God’s holy spirit, because they all came to nothing
Have there been witnesses of Jehovah on earth in every period of human history? What about the Dark Ages?