First Christian Nations Coin Replicas. Pewter cast replicas. Abgar VIII is known as Abgar the Great who converted to Christianity about 200 AD and declared Christianity the official religion of the city of Edessa. Armenia: legend tells of St. Thaddeus and St. Bartholomew bringing the gospel to Armenia. In the early 4th century, the Kingdom of Armenia became the first state to adopt Christianity as a state religion. Ethiopia: According to Eusebius the Ethiopian Eunuch (Acts:8:27 ) returned to Ethiopia to spread the gospel. About 330AD the Ethiopian King Ezana converted to Christianity, and decreed it for his kingdom.