Scribe:Castaway
A castaway is someone that God has cast off forever.
And thou, Solomon my son, know thou the God of thy father, and serve him with a perfect heart and with a willing mind: for the LORD searcheth all hearts, and understandeth all the imaginations of the thoughts: if thou seek him, he will be found of thee; but if thou forsake him, he will cast thee off for ever. — KJV, I Chronicles 28:9
So God can cast people away forever.
Behold, he breaketh down, and it cannot be built again: he shutteth up a man, and there can be no opening. — KJV, Job 12:14
God can shut up a man so that there can be no opening. Even Paul talked about that he could be castaway.
But I keep under my body, and bring it into subjection: lest that by any means, when I have preached to others, I myself should be a castaway. — KJV, I Corinthians 9:27
We see also in Jesus parable of the fish and the net that people can be cast away [48] and go to the lake of fire [50].
[47] Again, the kingdom of heaven is like unto a net, that was cast into the sea, and gathered of every kind: [48] Which, when it was full, they drew to shore, and sat down, and gathered the good into vessels, but cast the bad away. [49] So shall it be at the end of the world: the angels shall come forth, and sever the wicked from among the just, [50] And shall cast them into the furnace of fire: there shall be wailing and gnashing of teeth.
— KJV, Matthew 13:47-50
We see also in Romans 11 that people can be cut off like King Saul was.
Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in his goodness: otherwise thou also shalt be cut off. — KJV, Romans 11:22
It seems castaway could be about physical death as in the case of King Saul:
Moreover the LORD will also deliver Israel with thee into the hand of the Philistines: and to morrow shalt thou and thy sons be with me: the LORD also shall deliver the host of Israel into the hand of the Philistines. — KJV, I Samuel 28:19
Paul does talking about being a castaway. So it’s about loosing rewards in heaven.