Barnhouse and Martin wrote a book called the kingdom of the cults. Barnhouse and Martin in the 1950s met with many theologins during this time and spent hundreds of hours studying SDA material to determine the truth obout doctrines of the SDA church.
As a result of all of this the SDA church wrote a book called 'Questions on Doctrine' following a format of a question by evangelicals and an answer as to what the Adventist position is. At the same time Barnhouse and Martin wrote a book called the truth about Seventh day Adventists. Both books were sold in Adventist book stores and evangelical book stores. The result of all of this study is Barnhouse and Martin put out a statement saying SDAs are are truly christians forming part of the body of Christ and orthodox on central doctrins and they are herodox on some lesser doctrins.
There is a large sector of the SDA church that beleive Questions on Doctrine is heracy that have a large following in the church led by a theologin in America Pastor Andreson and in Australia a lay preacher called Bob Brinsmead led the awakening movement.These people all still remained church members but fought what they beleived the church was apostate. These people and there beleifs still exist in the church today and are what ?I would say are in some ways cultic.
In one SDA church we did have some JW studies become members of the SDA church and the reason they did become members is because they beleived after visiting other churches in the area they felt more comfortable at our bible study than anywhere else because they felt they could speak very freely and there opinions wouldnt be offensive to anyone there.
This openess is a two way sword because when Barnhouse and Martin studied SDAisn they found both trinitarian doctrin and Arian doctrine both with the church logo on it comming out of the churches publishing houses . The official SDA teaching is the trinity doctrine. Barry