Hi there, so you too is from SEA, am also a Filipino but here in the Philippines.. The context of John 15 is not about salvation, it's about fruit bearing. The word abide, abode simply means dwell. In this sense, not all that dwells can be be said to be a part. This means a lice in my hair/head cannot be said to be a part of my body. In essense v6. is referring to those who are not really a part and therefore they are not bringing fruit, fruitless, hence they are cast forth. The one that abides are of course the saved and bears fruit. No lost salvation for the saved but for the unsaved are worthy of cutting off since to begin with they are not a part of the branch.
God bless
God bless
Do you think any posibility the fruit bearer stop bear the fruit after bear for some time?