The most common religion in Albania is Islam, with the second-most-common religion being Christianity. There are also a number of irreligious Albanians. There are no official statistics regarding the number of practicing religious people per each religious group.
Albania has been a secular state since 1912, and as such, is "neutral in questions of belief and conscience": The former socialist government declared Albania the world's first "atheist state", even though the Soviet Union had already done so. Believers faced harsh punishments, and many clergymen were killed. Religious observance and practice is generally lax today, and polls have shown that, compared to the populations of other countries, few Albanians consider religion to be a dominant factor in their lives. When asked about religion, people generally refer to their family's historical religious legacy and not to their own choice of faith.
The 2011 census on religion and ethnicity has been deemed unreliable by the Council of Europe, as well as other internal and external organisations and groups.
History
Antiquity
Christianity spread to urban centers in the region of Albania, at the time composed mostly Epirus Nova and part of south Illyricum, during the later period of Roman era and reached the region relatively early. St. Paul preached the Gospel 'even unto Illyricum' (Romans 15:19). Schnabel asserts that Paul probably preached in Shkodra and Durrës. The steady growth of the Christian community in Dyrrhachium (the Roman name for Epidamnus) led to the creation of a local bishopric in 58 AD. Later, episcopal seats were established in Apollonia, Buthrotum (modern Butrint), and Scodra (modern Shkodra).
One notable Martyr was Saint Astius, who was Bishop of Dyrrachium, who was crucified during the persecution of Christians by the Roman Emperor Trajan. Saint Eleutherius (not to be confused with the later Saint-Pope) was bishop of Messina and Illyria. He was martyred along with his mother Anthia during the anti-Christian campaign of Hadrian.
From the 2nd to the 4th centuries, the main language used to spread the Christian religion was Latin, whereas in the 4th to the 5th centuries it was Greek in Epirus and Macedonia and Latin in Praevalitana and Dardania. Christianity spread to the region during the 4th century, however the Bible cites in Romans that Christianity was spread in the first century. The following centuries saw the erection of characteristic examples of Byzantine architecture such as the churches in Kosine, Mborje and Apollonia.
Christian bishops from what would later become eastern Albania took part in the First Council of Nicaea. Arianism had at that point extended to Illyria, where Arius himself had been exiled to by Constantine.
Middle Ages
Since the early 4th century AD, Christianity had become the established religion in the Roman Empire, supplanting pagan polytheism and eclipsing for the most part the humanistic world outlook and institutions inherited from the Greek and Roman civilizations. Ecclesiastical records during the Slavic invasions are slim. Though the country was in the fold of Byzantium, Christians in the region remained under the jurisdiction of the Roman pope until 732. In that year the iconoclast Byzantine emperor Leo III, angered by archbishops of the region because they had supported Rome in the Iconoclastic Controversy, detached the church of the province from the Roman pope and placed it under the patriarch of Constantinople. When the East-West schism separated the Western Christianity from Greek Christianity, southern Albanian regions retained their ties to Constantinople while the northern areas reverted to the jurisdiction of Rome.