"Brothers and sisters, if someone is caught in a sin, you who live by the Spirit should restore that person gently. But watch yourselves, or you also may be tempted"
Galatians 6:1
There is a difference between 'losing faith' and being 'caught in sin'.
Yes, there is a HUGE difference between being caught in sin and rejecting Jesus after believing! My point is to reject “once saved, always saved” because it seems clear that we CAN turn away from God after believing.
Of course, what makes it doubly hard is the lying sinfulness of the human heart! I am 100% certain, at a minimum, that there are people who now claim to be believers and who certainly SEEM to be believers who will reject Jesus later and then die unsaved. One can argue if they ever truly believed or not, but I think we should take all the warnings to stay faithful to the end seriously.
God knows who has and has not truly believed, but I am certain some think they believe and don’t because their own heart is lying to them and to others, while God is not fooled.
Tough subject and I know there are scriptures which seem to take both sides. Maybe that means God doesn’t feel the need to explain everything to us in detail in this life - and in the next, we will see God clearly and trust Him utterly, without questions or concerns!