Final answer:
Ecumenical councils possess the highest authority in Christianity, establishing church doctrines through consensus among world bishops in communion with the Pope. They historically addressed fundamental theological issues and reinforced papal authority. The Council of Nicaea, for example, defined the Nicene Creed, delineating the official orthodoxy regarding Jesus's divinity.
Step-by-step explanation:
The teachings of an ecumenical council are considered to have the highest authority in matters of Christian doctrine. These councils enjoy a special status because they embody the collective efforts of bishops from around the world, united in communion with the Pope, to delineate and clarify church doctrines. This collegial approach to resolving theological issues and combating heresies has been a critical aspect of church history, representing the universal ('Catholic') intentions of the church.
Historically, ecumenical councils were convened by emperors with the aim of uniting bishops to address divisive issues within the Christian faith. The first of these, the Council of Nicaea in 325, addressed the nature of Jesus's divinity, establishing the Nicene Creed and affirming Jesus as 'consubstantial' with God. The outcomes of ecumenical councils were intended to be applied universally throughout the Christian world, although linguistic, cultural, and theological differences presented challenges to this universality.
The role of the Pope in these councils, and in the broader context of church leadership, evolved over time. Initially, the archbishop of Rome was one among many church leaders but gradually asserted greater authority through claims of the 'Petrine Succession' and later through the recognition of papal supremacy. This process culminated in the Pope achieving the status of 'father' of the church, with ultimate authority in doctrinal matters, especially in the West. The ecumenical councils thus reinforced papal authority and shaped the orthodoxy of the church.