Final answer:
The Church determined the canon to unify Christian doctrine, consolidate its authority, and maintain orthodoxy amidst a variety of beliefs. This process helped control theological interpretations and guarded against heretical practices that threatened its spiritual dominance.
Step-by-step explanation:
The Church had to determine the canon to establish a set of unified doctrines and authoritative scriptures that would guide the faithful and maintain orthodoxy, especially given the diversity of beliefs and interpretations that had arisen. Establishing the canon also helped consolidate the Church's power by providing a definitive collection of texts for instruction and by standardizing beliefs across different linguistic and cultural contexts.
Furthermore, the process of canonizing the scriptures was intrinsically linked to the Church's role as the custodian of knowledge and the adjudicator of theological disputes, such as those addressed in the Council of Nicaea or during the investiture controversy.
In fierce efforts to maintain unity and power, the Church led by Popes would define orthodoxy and thereby sideline heretical views. Canonical texts played a pivotal role in maintaining control over the interpretation of Christian doctrine and safeguarding against competing religious practices, which were seen as threats to the Church's universal claim over Christian spirituality.