Korean Catholicism has a history of martyrdom and a church that began without the help of foreign missioners. The laity spread the faith without the help of the clergy until the first priest came from China.
In 1785 began the first persecution, about one year after the establishment of the church in Korea. In the first stage, the punishment was relatively light. Only the owner of the house was punished with exile. The noble class was pressured to give up their belief.
The persecution of 1791 was among the noble class who ignored the government's decree against the Catholic faith. The faithful rejected the ancestral rites and burned the ancestral tablet. These actions were condemned by their families and society as serious violations against filial piety. The Catholics who were involved were sentenced to death immediately. This event led many believers of the noble class to leave the Church. The persecution in 1791 was relatively small but it was a significant event in many aspects.
This was followed with a more aggressive mission attitude opposing the traditional culture which provoked tougher persecutions. They are the persecution of 1801, 1839, 1846 and 1866 which led to the death of about 10,000 martyrs. The loss of one Chinese priest and 12 French of the Paris Mission Society was a big blow to the church, (Taken from the Bishops' Website)
Both Catholic Weeklies had articles on a symposium on 'apostasy, exile and witness' of the first Christians. The research on the numbers of those who gave up their newly found faith in the face of death is not complete—government numbers differ from those of the church.
Apostasy is the word that we use with those who once believed and for various reasons turn away. This situation does not only appear in times of persecution. Peter denied he knew Jesus three times but we can also call it apostasy when we distance ourselves from God by our actions because of personal circumstances, and fail to live as Christians.
At the symposium, speakers pointed out when speaking about the time of persecution we should avoid understanding it as an issue of good and evil— faith and apostasy. Emphasized was to look at the history of the times understanding the situation in which the people lived.
The records show that there were more apostates than martyrs. However, many of them such as the father of St.Andrew Kim repented and this was the case for others. In the persecution of 1801 the rate of apostates among those arrested reached 62 percent. In 1839—48% and in 1866—54%.
Despite their apostasy, many of them were not released but sent into exile. In particular, 400 people were exiled during the 1801 persecution and died in exile. Among the arrested Christians, not only did they apostate for their lives, but also others went along with the authorities to ferret out the Catholics. Three of the informants were listed who brought great harm to the church.
Believers in the time of persecution called the informants Judases. After the freedom of religion was acknowledged. Some of these informants repented of their actions and were even witnesses of the death of the martyrs for the church. The families of those who were killed during the persecution found it very difficult to accept these informers back into the community of faith even after their repentance, a very sad situation.