Hebrews 9:27 says that all men are appointed to die once. Considering this, some have asked: How can one die a second death? How many times can one die?
First, baptism is symbolic of death (Romans 6:2-11) and so is "dying daily," as Paul describes the sacrifices of the Christian life (ICorinthians 15:31). Paul mentions this latter death in the context of the resurrection chapter to emphasize our need to crucify the old self daily and renew or resurrect the inner man as symbols of actual death and resurrection (see II Corinthians 4:16-17). In this sense, we die every day of our lives.
When speaking of great embarrassments, many have used the phrase, "I died a thousand deaths." That is just what God expects of us if we are to reach maturity of thought and conduct! Each of these deaths is just as difficult and excruciating as the one before, and thus Paul describes them as crucifixions (Galatians 5:24). These play a major role in overcoming, and it is never easy.
Apart from symbolism, the general rule is that we each die physically at least once and then await the resurrection to eternal life. But some few humans have already died twice! Lazarus, Dorcas, Eutychus, those who came out of their graves when Christ died and others were physically resurrected and physically died again.
It is conceivable that some few might even die three times! If those who were resurrected physically were converted and accepted for the Kingdom, they will be resurrected when Christ returns - changed "in the twinkling of an eye" into immortal spirit beings (I Corinthians 15:52). If they were not called and converted - not yet having had an opportunity for salvation - they will come up in the second resurrection to be alive a third time. At the end of that life they will then be either changed to spirit or die in the Lake of Fire, a third death.
Why, then, does Revelation 20:14 call the Lake of Fire "the second death"? The emphasis is on the fact that it is a permanent death. Once a person experiences the second death, no hope remains for another resurrection. However, for a few it could represent a third physical death.
The point is that all of us are appointed to die at least once! Even those "blessed and holy" individuals who are alive and changed at Christ's return will go through a kind of death. As Paul writes, "For this corruptible [body] must put on incorruption, and this mortal must put on immortality" (I Corinthians 15:53).
The Third Resurrection: What Is Its Value?