This question was asked in a previous post. I wrote to the Worldwide Church of God website and the answer is posted below:
Greetings Mary, Thank you for your message. Herbert Armstrong was not affiliated with the Jehovah's Witnesses. However, during the years when Armstrong formed his theological ideas, he came into contact with various religious groups and their writings and teachings. These included Jehovahs Witnesses, Seventh-Day Adventists, the Church of God (Seventh Day), the Seventh-Day Baptists, Pentecostals as well as evangelical Protestant groups and individuals. For example, he studiously read and admired the works of Charles Finney, the influential nineteenth-century American evangelist. Armstrong and his wife attended various churches. I hope this answers your question. Your interest is appreciated. Paul Kroll Personal Correspondence So there it is...from the horse's mouth so to speak.