Trial of Sin

The Trial of Sin is a mock "holy trial" used by both the Anglican Church and the Roman Catholic Church to determine if a person is a sinner, and is used as a test to see a person's faith in God. The trial is set-up in such a way that no matter the outcome, the accused will always be found guilty. According to Stiyl Magnus, it has now been banned, although the Roman Catholic Church is still using it.

Principles
According to Stiyl, a member of a church cannot be killed because the person is a believer of God, however, the person can be executed when that person is someone who has disobeyed the Word of God, such as sinner, witches, and disillusioned believers. The trial is used to determine whether or not the accused person is guilty of disobeying the Word of God, however, it was created in such a way that anyone who is forced into the trial will always be found guily. This is done by making a test that is impossible to fulfill in any normal means such as: forcing someone to hold a hot metal rod, if the person is not guilty of the crime then God will protect the person from harm, however, if the person is harmed then he is guilty. Even then, if there is a possibility that the accused will go unharmed then the accused will still be found guilty, as it will be rationalized that the devil was the one protecting the accused.

To the Roman Catholic Church, the trial would last about 2-3 days before the execution of the accused, and has to be in Rome in accordance to proper procedures. Agnese Sanctis describes that the procedures for the test is appalling, and is much worse in the Anglican Church.

Orsola Aquinas Rescue Arc
The test is described in detail by Stiyl Magnus to Kamijou Touma, after Orsola Aquinas' recent capture by the Roman Catholic Church. The trial would've been used in order for the Roman Catholic Church to justify the execution of Orsola Aquinas, a fellow member of the Roman Catholic Church. Agnese's forces beating up Orsola in her church is somewhat of a simulation of the trial, and was told by Agnese that it would be preferrable for Orsola to die in the church instead of being forced to stand trial. This fate would've befallen Orsola if not for her timely rescue later.