“Everyone that pushes ahead and does not remain in the teaching of the Christ does not have God [that is, is not in union with him, has no fellowship with him; compare 1 John 1:6]. He that does remain in this teaching is the one that has both the Father and the Son.

At the time that they had to be disfellowshiped they were apparently following a course like such ones or at least manifesting a similar sentiment. As the publication Organization for Kingdom-preaching and Disciple-making says on page 172: “Any baptized person who deliberately pursues a course of immoral conduct is actually rejecting the teachings of the Bible, just as much so as one who teaches others contrary to what the Scriptures say about the identity of God, the provision of the ransom, the resurrection, and so forth. (Compare Titus 3:10, 11; 2 Timothy 2:16-19.)”