Lordship and the Folly of Discipleship/Salvation synonymy

A central issue with LS is a failure to accurately distinguish discipleship from salvation. A passage that clearly shows a negative example of the difference is John 6:66. "Disciples" abandoned Jesus precisely because they didn't believe him, yet the word is the same as is used for disciple some 260 other times. Disciples aren't necessarily faithful believers , so the concepts are clearly not as synonymous as the average LS proponent would have us believe. Allowing the Bible to define it's own terms and their use --discipleship isn't salvation, and salvation isn't discipleship -- it's folly to enjoin them as functionally synonymous.