The Reformed Church of God is a splinter group which broke from the Worldwide Church of God. This group taught the following (which, as one can see from the bolded parts, are unBiblical, and therefore unchristian teachings):
Identification of the British and American people as descendants of two sons of Jacob: Ephraim and Manasseh.
Belief that the term "British" is derived from the ancient Hebrew word "beriyth" (covenant).
Belief that the term "Saxon" originated as "Isaac's Sons"
As the "lost" ancient Israelite tribe of Dan spread across Europe, they named many rivers, towns etc. after themselves (e.g. Danube River, Denmark, Donegal).
Rejection of the traditional Christian concept of the Trinity as being of pagan origin. Armstrong accepted a modified Arian view of the nature of God -- the teaching by Arius in the late third century CE. They believed that deity consisted of a dual divinity: The Eternal (their translation of the Hebrew name of God: Yahweh) and Jesus. He taught that that the Holy Spirit is a power, not a person. He promoted the concept of the "Family of God", which consisted of Jehovah, Jesus,
and human believers in the WCG who became Gods.
At the crucifixion, Jesus' body and spirit died for three days and three nights. He was later raised by the Father and his human body was transformed into a spirit body.
Belief in Jesus is a necessary and sufficient requirement for salvation and the attainment of Heaven.
Members will be rewarded in heaven according to their works, including how closely they followed the commandments of God (the 10 Commandments, dietary laws, holy days etc.).
Identification of the WCG with the "Philadelphia church" in Revelation 3:7.
Rejection of the concept of Hell as being pagan in origin.
People who die without meeting the dual requirements (faith and works) for salvation will be resurrected, and taught Biblical truths. If they still do not accept the teachings, they will be cast into a lake of fire and cease to exist.
http://www.religioustolerance.org/wwcog.htm
Thus, I would classify the Reformed Church of God as a Christian-based cult, and would advise you, RWA, or anyone else, to stay away.
Here is a link to some reading on the Moffat version.