RECOGNIZED CHRISTIAN CULTS
A large portion of Christendom recognizes the JW's and used to recognize the SDA and MORMON's as Christian "cults." However, SDA are no longer recognized as a cult (Walter Martin removes them from this classification) and Mormons are being more accepted as a Christian group. But why were they regarded as "cults" in the first place? Because they reject the Biblical doctrine of the Trinity or eternal punishment in hell?
JW, SDA, and LDS are cults not because of their false doctrines, but because of the source of their doctrines (founders or leaders who claim authority on par with the Bible, especially those basing doctrines on claims of extra-biblical revelation).
All extra-biblical doctrines are false, but just having a false doctrine doesn't make a church a cult. It just makes the church mistaken (e.g. AoG). Or, maybe faithless (e.g. PCUSA).