About 249 AD, the situation of the Christians took a sharp turn for the worse. The year 247 AD marked 1000 years since the founding of the city of Rome: the Millennium. A lot of people were frightened and thought this might mean the end of the world. Many Christians thought it might mean the Second Coming of Christ. But the world did not end.
After the Millennium was over, the Roman Emperor Decius announced that every person in the Empire should sacrifice to the gods to show how thankful he or she was that the world hadn't ended. Decius seems to have meant this as a sort of nice idea, like announcing Grandparents Day.
Sacrifice certificate on papyrus
from Oxyrhynchus, in Egypt, dating to the Decian persecution
(about 3 inches wide)
In Carthage, the local town council used Decius' law to find out if people were Christians. Everybody had to come to the middle of town, to the forum, and sacrifice to the gods (by dropping some incense into a fire and saying a prayer). Then they would get a piece of papyrus saying they had done it (a certificate). But Christians would not sacrifice to another god. So anyone who didn't have a certificate was a Christian and could be killed for breaking the law.
Many Christians were frightened by this and went to sacrifice. Other Christians bribed someone to get a certificate without sacrificing, or they forged one. Some left town and moved somewhere that didn't take this law so seriously. But some Christians did stand up for their beliefs and refused to sacrifice. Many of them were thrown in jail, and some of them were actually killed.
Cyprian, the bishop of Carthage, insisted that if you wanted to go to heaven you could not get a fake certificate, or sacrifice, or even run away. But when the police came for him, he ran away to the hills. He said it was okay for the bishop to run away because he was so important, but a lot of people made fun of him anyway and called him a coward. Finally he came back and the Roman police cut off his head.