In verse 22, Paul speaks of “sav[ing] some.” Sometimes we have an automatic tendency to think of eternal salvation, or at the very least justification, whenever we hear the words “save” or “saved.” However, that is only one facet of the Greek word translated as “save,” sozo (Strong's #4982), whose basic meaning is “to make safe.” It can be expanded to mean “to deliver or protect, either literally or figuratively.”
This word is frequently used in reference to physical deliverance from a dangerous or undesirable situation, and is often translated as “heal,” “preserve,” and “make whole.” When healing people, Jesus would tell them, “Your faith has made you whole.” He was essentially saying, “Your faith has saved you”—but the salvation was a physical one. The person was saved from a condition of misery.
In the highest sense, a person is not ultimately saved—“safe”—until he or she is no longer subject to death or to sin, which earns death. That is, we are not truly safe until “this corruptible has put on incorruption, and this mortal has put on immortality” (I Corinthians 15:54). Until resurrected or changed at Christ's return—until we are “like Him” (I John 3:2), and “death is swallowed up in victory” (Isaiah 25:8)—we are subject to the corruption of our human nature, the breakdown of our physical bodies, and the cessation of life, all things that keep us from being eternally safe. Until we are spirit beings, we will always be in need of deliverance, protection, healing, and restoration. Even the salvation that takes place upon our repentance—the forgiveness of our past sins—does not guarantee our future safety, for until we take our final breath, it is possible for us turn away from God and reject His way of life.
What kind of salvation is Paul talking about in I Corinthians 9? Since no man is saved eternally at the point of conversion, he is not referring to eternal salvation. We also know that he could not have meant justification here either, because even an apostle does not have the power to justify. Nor was he given the authority to impart true belief. Only those whom God appoints to eternal life at this time are going to believe (see Acts 13:48). So that sort of saving is not what Paul is talking about.
Before we get to the full explanation, we need to understand how this passage fits with the rest of the epistle. I Corinthians 8-10 relate to the controversy over eating meat offered to idols. Paul's basic teaching throughout these chapters is that it was far better for the Corinthians to deny themselves a perfectly lawful thing than to risk causing a brother to stumble. Through much of this instruction, he uses his own pattern of self-denial as an example, showing in various ways that he would go without lawful things to keep from causing unnecessary offense.
Thus, if he were interacting with the Jews, he would deny himself things that could be offensive to them but that technically would have been fine. It is not that he would compromise with God's standards, but he would limit himself for the sake of not turning people away. This is what he was doing to gain them. By these means, he was working for a more profitable relationship. His basic point in the overall context is that, if he were willing to do this to gain people who were not even converted, then the Corinthians should be willing to limit and restrain themselves for the sake of gaining their own brethren. A person who is “gained” is more likely to hear what we have to say, so we may be used to help them in some way.
So what does Paul mean by writing, “I have become all things to all men, that I might by all means save some”? He may have been referring to their eventual salvation, which he might play a part in, but which he could not actually claim as having brought about. As he had previously written: “I planted, Apollos watered, but God gave the increase. So then neither he who plants is anything, nor he who waters, but God who gives the increase” (I Corinthians 3:6-7).
However, there is a type of “saving” that Paul could have a hand in through his preaching:
My brothers, if any among you strays from the truth, and someone turns him back, he should know that whoever turns a sinner from the error of his way will save his life from death and cover a multitude of sins. (James 5:19-20)
James is not referring to eternal salvation or justification. He means making a man safe by helping him to stop a sin. If a person is sliding into apostasy, and someone turns him back, a type of salvation has occurred, for the one who had been going astray is now on a safer trajectory. If an individual helps another avoid or overcome any sin, a type of salvation has occurred because there is always greater safety where sin has been diminished. This salvation is only a shadow of the kind that God gives, but a saving nonetheless occurs anytime protection or deliverance is provided.
Thus, I Corinthians 9:19-22 shows that, wherever possible, Paul practiced self-denial so that he could gain a positive rapport with others. In this way, he might help them because his preaching of the truth could stir repentance in some area. He is not suggesting that through his preaching or example a person would be justified and brought into a relationship with God, but that his life would be better because there would be at least a little less enmity toward God and His way.
Without compromising, Paul kept the door open so that he could preach, and perhaps his preaching would protect or deliver someone in a small way, even if God was not calling the individual. Nevertheless, Paul was not bringing people into a relationship with Christ, nor is he suggesting that we try to do that either.