The general rule in the Greek penal law requires witnesses to take an oath on the Gospels. Accordingly witnesses are a priori considered to be of the Orthodox Christian faith. Individuals who have another religion or who do not have a religion must declare this explicitly to the judge during the hearing. When the witness follows a religion which is recognized or tolerated by the state, he or she can follow the oath taking rules of this religion. When the religion of the witness has no oath taking rules or when the witness has no religion a solemn declaration is sufficient.
In Dimitras v. Greece the Court examines whether the Greek legislator gives the possibility to witnesses to opt for the solemn declaration instead of taking the oath, taking into account the negative aspect of the religious freedom protected by article 9 ECHR.