During the second and third centuries, there were controversies over the nature of Christ. So, the church settled these issues by stating that Jesus had both a divine and human nature in the First Council of Nicaea in AD 325. This was followed by the Council of Constantinople, in AD 381. After the second Council, the focus of some was to define: how could the two individual natures of Christ exist in one person?
The third ecumenical church council was called at Ephesus, in 431, for the aim of ending this controversy between the schools of Antioch and Alexandria. Finally, the emperor Justinian, persuaded that the safety of the empire required a settlement of the controversy about the nature of Christ, permanently closed the schools at Antioch and Alexandria, the two hubs of controversy.
At a second Council of Constantinople, in AD 553, the church decided upon the ending of Monophysitism, which went into permanent division and continues to this day in Christian sects such as the Jacobites, the Copts, and the Abyssinians.
The Reformation era found that Protestant church and the Roman Catholic church in ultimate agreement on the Trinity and the nature of Christ. The Nicene Creed was generally approved by both. Luther taught a shared exchange of characteristics between the two natures, so that what was distinctive of each became common to both.
Everything human in Christ was seized by the divine nature, and humanity acknowledged what belonged to the divine nature. The Reformed churches stressed the communion of the divine and the human in Christ.
Two minor Reformation groups diverged from the Nicene position. The first of these was the Socinians, who believe in the basic Monarchian idea that a divine Trinity is unthinkable. Modern Unitarianism preserves this concept.
The second group was the Arminians, who adopted a view alike, in some aspects, to that of certain earlier sects, that the Son is secondary and lesser than the Father. This view is likewise echoed by numerous Christian sects in our present day.
In His service,