At no time in Scripture (after his conversion) did Paul ever give any hint of any doubt of him being unsaved. You are stating here that Paul is thinking that he may be unsaved! Absolutely ludicrous!!HP: Neither does Scripture state, imply, or give grounds for your very deterministic leaning interpretation that would eliminate ‘castaway’ from carrying the connotation of ending up making shipwreck of the faith and as such not making heaven Paul’s final eternal home.
1 Corinthians 9:25-27 And every man that striveth for the mastery is temperate in all things. Now they do it to obtain a corruptible crown; but we an incorruptible. I therefore so run, not as uncertainly; so fight I, not as one that beateth the air: 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.
It is a personal illustration. Look at all the first person pronouns: "I"
He is using athletic illustrations:
One from running a race.
One from boxing.
The other from training for these athletic events.
The context is in Corinth, Greece, and likely a reference to the Olympic Games--in Greece where they originated. The athletes all competed for a corruptible crown, one that faded away. But that didn't mean they weren't athletes if they didn't win. They trained. He kept his body fit--under subjection. The flesh must be subdued. One must submit himself to the Spirit, not the flesh. We are always in a race. Sometimes an athlete disqualifies himself from the race. But he still remains an athlete. In some sports one can disqualify themself simply by a false start.
It is not hard to be set on the shelf in the ministry. I know of a pastor that fell into adultery. He didn't lose his salvation. But he did lose his ministry. He was no longer qualified as a pastor, and had to step down. Because of his action (giving into the flesh rather than the Spirit) he was a "castaway", set on the shelf--in other words, his ministry for the Lord and to others became severely limited.
But he did not lose his salvation. The context is not speaking of salvation.
Paul's salvation was never in question.