The word spiritualism involves both communication with evil spirits and adopting the methods they use in twisting Scripture.
The Adventist Message has been built firming upon the literal rule of interpretation. All our doctrines were developed by taking all texts together and harmonising their meaning in plain language, letting the Bible alone define terms and symbolism when a literal meaning is impossible.
The most obvious place where a literal rule applies is in the terms Father and Son. If Jesus is not truly the Son of the Father, then this sets a platform to spiritualise away all our teachings.
The Sanctuary, victory over sin, the nature of Christ, roles of men and women are all spiritualised away. This train of heresies finds it source in spiritualising the Father and Son so that these terms have no relational meaning.