The saved Galatians left.The whole counsel of God does not include pitting scripture against scripture. We need to properly harmonize scripture scripture in order to reach the proper conclusion on doctrine.
You say 1 John 2:19 means they weren't saved.
That's pitting scripture against scripture.
My doctrine does not do that.
You left off the first part of the verse:1 John 2:24 actually supports my argument. If what you heard from the beginning abides in you (descriptive of genuine believers) you will also abide in the Son and in the Father. *Also see 1 John 4:13.
"24 As for you, let that abide in you which you heard from the beginning." - 1 John 2:24
That is not descriptive.
We know it's not a descriptive passage, just by the simple fact that the believing Galatians left. Apparently, 1 John 2:24 was not very 'descriptive' of those genuine believers. Your doctrine pits scripture against scripture.