I think 1 Corinthians 9:24-27 is a good example of this:
9:24 Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain. 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.Paul is definitely talking about salvation here, and he mentions a continual struggle with his body--"lest he should be a castaway"--which I can't interpret any other way but as a concern with losing his own salvation.
Paul also said in Philippians 2:12 to "work out your own salvation in fear and trembling"
"9:24 Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain. 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."
Paul is definitely talking about salvation here, and he mentions a continual struggle with his body--"lest he should be a castaway"--which I can't interpret any other way but as a concern with losing his own salvation.
I can see where you're coming from. The same passage from the NIV bible says it this way:
"24 Do you not know that in a race all the runners run, but only one gets the prize? Run in such a way as to get the prize. 25 Everyone who competes in the games goes into strict training. They do it to get a crown that will not last; but we do it to get a crown that will last forever. 26 Therefore I do not run like a man running aimlessly; I do not fight like a man beating the air. 27 No, I beat my body and make it my slave so that after I have preached to others, I myself will not be disqualified for the prize.
Paul is using a local metaphor, the Isthmian games. Winners of events were given a wreath of pine to wear as a crown. Obviously, it would eventually wilt. Another interpretation would be that the "crown" and "the prize" refer to rewards in Heaven. Many other verses speak of works-based Heavenly rewards. For example:
1 Cor. 3:12-14 - "12 If any man builds on this foundation using gold, silver, costly stones, wood, hay or straw, 13 his work will be shown for what it is, because the Day will bring it to light. It will be revealed with fire, and the fire will test the quality of each man's work. 14 If what he has built survives, he will receive his reward."
2 John 8 - "8 Watch out that you do not lose what you have worked for, but that you may be rewarded fully."
But, I agree that good arguments could be made on both sides of this one.
Paul also said in Philippians 2:12 to "work out your own salvation in fear and trembling"
Phil. 2:12-13 - "12 Therefore, my dear friends, as you have always obeyed—not only in my presence, but now much more in my absence—continue to work out your salvation with fear and trembling, 13 for it is God who works in you to will and to act according to his good purpose."
Since both verses comprise one thought, I do think that God is talking about human works. I suppose our interpretations come down to "working for salvation" vs. "working with our already established salvation, in order to do God's will".
"Work out" could mean "seek after" or it could mean "do God's work through". I admit it is a tricky verse, and could be legitimately interpreted in more than one way.