Strandakirkja Altar

Christianity (from the Ancient Greek: Χριστιανός Christianos and the Latin suffix -itas) is a monotheistic and Abrahamic religion based on the life and teachings of Jesus Christ as presented in canonical gospels and other New Testament writings as well as the Old Testament. Most adherents of the Christian faith, known as Christians, believe that Jesus is the Son of God, fully divine and fully human and the savior of humanity prophesied in the Old Testament. Consequentially, Christians commonly refer to Jesus as Christ or Messiah.

The foundation of Christian theology is expressed in the early ecumenical creeds which contain claims predominantly accepted by followers of the Christian faith. These professions state that Jesus suffered, died, was buried, and was subsequently resurrected from the dead in order to grant eternal life to those who believe in him and trust him for the remission of their sins. They further maintain that Jesus bodily ascended into heaven where he rules and reigns with God the Father. Most denominations teach that Jesus will return to judge all humans, living and dead, and grant eternal life to his followers. He is considered the model of a virtuous life, and his ministry, crucifixion, and resurrection are often referred to as the gospel, meaning "Good News" (from the Greek: εὐαγγέλιον euangélion).

It is believed that Iceland was Christianised in approximately 1000 AD. In Icelandic, this event is known as the kristnitaka (literally, "the taking of Christianity").

The earliest Christian observance in the country in all likelihood began with the arrival of the first settlers during the settlement of Iceland in the 9th and 10th centuries AD. Some of them were from the British Isles and had adopted Christianity through their contact with the Irish. However, the vast majority of the initial settlers were pagan, worshipping the Æsir (the Norse gods), and organized Christian observance probably died out within a generation or so.

Christology (from Greek Χριστός Khristós and -λογία, -logia) is the field of study within Christian theology which is primarily concerned with the nature and person of Jesus Christ as recorded in the canonical Gospels and the epistles of the New Testament. Primary considerations include the relationship of Jesus' nature and person with the nature and person of God the Father. As such, Christology is concerned with the details of Jesus' ministry, his acts and teachings, to arrive at a clearer understanding of who he is in his person, and his role in salvation. A major component of the Christology of the Apostolic Age was that of Paul the Apostle. His central themes were the notion of the pre-existence of Christ and the worship of Christ as Kyrios (Greek: Lord).

Following the Apostolic Age, there was fierce and often politicized debate in the early church on many interrelated issues. Christology was a major focus of these debates, and was addressed at every one of the first seven ecumenical councils. The second through fourth of these councils are generally entitled "Christological councils," with the latter three mainly elucidating what was taught in them and condemning incorrect interpretations. The Council of Chalcedon in 451 issued a formulation of the being of Christ — that of two natures, one human and one divine, "united with neither confusion nor division." This is called the doctrine of the hypostatic union, which is still held today amongst most Protestant, Catholic, and Eastern Orthodox Christians, referred to as Chalcedonian Christianity. Due to politically charged differences in the 4th century, schisms developed, and the first denominations (from the Latin, "to take a new name") formed.