Assuming that "every slave and every free man" refers to true Christians, what might God's people do in these caves? Hopefully, they would be a light to those around them (Matthew 5:14). Armed with far more knowledge about God and His plan than their masters, God's people will be able to put the horrifying events into perspective for the already-humbled cave-dwellers. The caves will be not so much a "place of final training" as a venue to serve others. For example, God's people might
1. Assure others that Christ will soon end the maddening chaos by establishing His rule on earth.
2. Tell them the living can expect to see His return—"every eye will see Him" (Revelation 1:7).
3. Notify them that, at His return, they can expect to see God's people rising in the air to meet Him (I Thessalonians 4:17).
5. Enjoin them to make their way to Jerusalem when conditions begin to settle down, where they will be taught by Christ, the Lamb.
Since every eye will see Christ return (Revelation 1:7), we can deduce that the rigors of the Day of the Lord will open the caves, exposing them to the atmosphere, or perhaps events will force their inhabitants out into the open. The cavemen will see Christ return in power and great glory (Matthew 24:30). As the living among God's people rise to meet Christ, will they say to their fellow cave-dwellers, "See you in Jerusalem"?
Though they entered the caves with a degree of resignation, supposing they would eventually perish there, the presence with them of "every slave and every free man" will bring about a change in their thinking, arming them with more complete knowledge about God's plan and will. Once Christ returns, they will be motivated to make their way to Jerusalem as soon as it is feasible.