United was begun by many who left the Worldwide Church of God after they abandoned biblical doctrine. It's the largest of the so called "splinter" groups that broke off Worldwide.
From UCG's website A Brief History Of United Church of God.
Many of the current ministers and members of the United Church of God were once members of the Worldwide Church of God, a nonprofit corporation under the leadership of Herbert W. Armstrong until his death in 1986. A subsequent unwarranted shift toward nonbiblical practices and beliefs led numerous ministers and members to leave the fellowship of that organization.
Concerned with uneven administrative practices of the former assembly, more than 100 ordained ministers developed a new administrative structure that was more directly accountable to members and the ministry.
Let me know if you have any other questions.
Thank you for responding. Definately not followers of Tkachism then and I presume put off by Flurry’s axe-grinding perhaps? I’ve bookmarked it all for further study FRiend. Thanks again and God bless.