Truly I hope the dispute is just a matter of semantics.
The sheep pens in John 10 are indeed an excellent metaphor for the theological boundaries of Judeo/Christian doctrines and traditions.
And of course, the more people add to and take away from the words of God - or the more they elevate particulars of their beliefs - the more walls they throw up between themselves, like sheep pens within sheep pens:
Since I'm one of those who particularly enjoys the open pasture (Psalms 23) I've been called both - also "apostate" "Jesus freak" "cultist" and even "Satanic."
It never offends me to be called such things. I write it off as yet another manifestation of the "observer problem." Indeed for me it is all joy even though it comes from a brother or sister in the faith, a fellow sheep.
And I pray that on this sidebar, there is no intent to invoke the terms "gnostic" and "heresy" within the various sheep pens of the Judeo and Christian sheepfolds - but rather in the historical and cultural context of Western civilization.
To God be the glory, not man, never man.
LoL.. me too(prayer)... Humans are now and have been busily sorting themselves into sheep pens and sheep pens within sheep pens for millenia.. Its a wonderful thing.. Pure genius actually.. After fully being sorted and convinced indoctrinated and settled, comfortable and relaxed in a sheep pen.. denying their selection(choice) would be hard to do..
Is God(in his plan) awesome or WHAT?..