C.J Koster, a South African ex-Christian Pastor.  Which according to the institute which Koster started, the"Institute for Scripture Research (ISR)"; It wasn't till 1978 when Koster became "disillusioned by the syncretism between the original Nazarene faith and pagan sun-worship, which resulted in Christianity as we know it today."  At which point, Koster began his commission of restoring the long lost untainted "Nazarene faith" back to the corrupt pagan-Church of today. Koster's earliest teachings, beginning in 1978 -1986 can be listened to and downloaded (here).  It wasn't till 1986, that Koster had put his doctrinal teachings down on paper; titled "Come out of Her My People". And according to (ISR); "Come Out of Her My People is essential for any believer who has a sincere desire for Truth. It is of utmost importance to every Christian believer who wish to return to the pure, unadulterated faith once delivered to the set-apart ones who practiced the teachings of the Messiah."
Much of Koster's book "The Final Reformation/Come out of her my people" is a history lesson on the origins of pagan-sun god worship and its infiltration into the Church, much like Alexander Hislop's 1853 (the Two Babylons). But, contained within Koster's book, there is an introduction into a "re-newed" biblical doctrine, which according to Koster was hidden behind a mistranslation of a single word of the Hebrew and Greek bible translations into the English versions. Which according to Koster is the root of the cause of this pagan transformation of the Christian Church, also the answer to getting "My people out of her".  It is here on pg. 18 of Koster's "The Final Reformation/Come out of her my people" where we find the first usage of this "re-newed" doctrine;
 
pg. 18 -"Please note: Renewed Covenant is the better rendering, for Heb. 8:8 is quoted from the Hebrew of Jer. 31:31. The Hebrew chawdawsh is derived from the verb chawdash, which means "renew" (see any Hebrew lexicon). Even the Greek equivalent, kainos, is best rendered as "fresh" or renewed"."
 
 let's jump now to 1993. Where we find the first ever published Bible translation containing this "renewed covenant doctrine".  You probably guessed it, published by (ISR) Koster himself, titled "the Scriptures".  
 
The "Renewed Covenant Doctrine" itself is nothing new (pun intended). The (RCD) core is "the same Old Covenant Law but in a New Covenant"; therefore a "renewed" covenant. This same doctrine is as old as the "New Testament" itself, found in Acts 15:1 and 15:5;
Acts 15:1 And certain men which came down from Judaea taught the brethren, and said, Except ye be circumcised after the manner of Moses, ye cannot be saved.
Acts 15;5 But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses.
From a biblical stand point we have the birth of the "renewed covenant doctrine" (RCD) in Acts 15. Which was taught by a "certain sect of Pharisees from Judea "WHICH BELIEVED"; teaching the brethren, the only way to be saved is to be circumcised after the manner of Moses, and to keep the rest of the Law of Moses, i.e. "The Renewed Covenant". The Apostle Paul calls this certain sect of Pharisees; the Concision in his letter to the Philippians chapter 3, and to beware of them.  Koster on the other hand is not the original sower of this "renewed" seed, but is in fact the late bloom of it.  This (RCD) didn't stand with the Apostles in their time, as we see in the Apostle Peter's response against this (RCD), as being troubling and burdensome, to say the least.  Also they "the Apostles" teach no such Covenant.  Acts 15...
 Now according to the New Testament writings, the Concision and their (RCD) has already begone to spread throughout the lands by Acts 15.  It wasn't long before the Apostle Paul was writing the foolish Church of Galatia that they have been "bewitched" unto "another gospel (RCD)" troubling them with a perversion of the true gospel of Christ "the New Covenant Doctrine"(NCD). The Apostles written much concerning this "Concision sect" and the deception of their (RCD).
-Galatians 1:6–7 KJV
 
“1:6 I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: 7 Which is not another; but there be some that trouble you, and would pervert the gospel of Christ.”
It wasn't long till this Concision and their (RCD) had lost steam, once Catholism had entered on stage, they were swallowed up by a much bigger beast.  But since their retreat into darkness in the early first centuries, they have crawled out reemerging in the year of 1978, through the man named C.J Koster.  By 1986, the (RCD) has found a new voice, through the writings of Koster in his book "The Final Reformation/Come out of her my people". By 1993, the (RCD) has its very on Bible translation, called "the Scriptures".  It is here in the mid 1990's, where we find the Concision sect of the first century reemerged into the 21st century as "The Hebrew Roots". 

The research by Dr Chris Koster resulted in his publication of the book "Come out of her My people" (previously named 'The Final Reformation') and its translations into Afrikaans, "Gaan uit haar uit My volk" (previously named 'Die Finale Reformasie') and the Spanish "Salid de Ella Pueblo Mio". Before his passing away, Chris Koster donated his research and the rights to these publications to Institute for Scripture Research, a Section 21 non-profit organisation registered in South Africa.

After completion of these works, Chris Koster established Institute for Scripture Research (ISR) together with seven other directors, chaired by C.J. Koster until 1995. The main purpose of establishing the ISR was to publish "The Scriptures" translation, steered by Dr Koster, with the assistance of theologians, rabbis and other Hebrew and Greek scholars across the world. The Scriptures was first published in 1993, with improved editions published in 1998 and 2009.

http://cj-koster.com/about.html

 During the years 1978 - 1995 he was disillusioned by the syncretism between the original Nazarene faith and pagan sun-worship, which resulted in Christianity as we know it today. During those years Chris regularly recorded Sabbath meeting messages and distributed them across the world.