During the first century the Romans had many, many slaves. The Romans conquered many nations and the people of those nations often became slaves. Some slaves were treated very well while others were treated badly. It was possible for a slave to become a freeman. There were several ways that this could happen but we will not discuss those here.
When a slave became a freeman, he was given a special cap. This cap was made of felt and was shaped like half of an egg. It fit very closely to the head. This cap was a sign of his freedom, and was known as the freedman's cap. When anyone saw the cap they would know that he was a free man and not a run-away slave.
There was a festival called Saturnalia. During this festival it was customary for everyone to wear the freedman's cap. One reason for this was to show that all men were equal under Roman law. Another reason was to demonstrate the freedom of the season, and compassion and good will were to prevail during the festival. But the slaves all knew that it was only for a few days. In reality, they were not the same as Roman citizens.
In Galatians 3:27-28, we read, “For as many of you as have been baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.” All of those who have been baptized into Christ are equal in Christ. In John 8:32-34, we learn that through obeying the truth we are made free. This freedom is not just for a few days of a festival. This freedom is for eternity if we will be faithful in this life to God's Word.
In Ephesians 6:13-17 Paul gives us the armor of the Christian. It is interesting that we are to have a helmet of salvation. This helmet of salvation is our freedman's cap. Salvation says that we are saved from sin. We are no longer a slave of sin.
(Mark McWhorter , Copyright 2002, Published by The Old Paths Bible School, http://www.oldpaths.org)