Final answer:
Apostolic Succession is the Christian belief that the church's authority is derived from the apostles, maintaining doctrinal continuity and spiritual legitimacy. Petrine Succession refers to the Roman bishops' lineage from the apostle Peter. The doctrine is considered vital for upholding the church's authenticity and connection to its founders.
Step-by-step explanation:
Apostolic Succession is a religious doctrine, particularly within Christianity, that holds that the authority of the church's bishops and the pope is derived directly from the apostles. This succession ensures that church teachings and ordinations are rooted in the continuity of apostolic tradition. Petrine Succession, a related concept, refers specifically to the lineage of leadership starting from the apostle Peter, to whom Christ is believed to have given the symbolic keys to heaven, thereby establishing the first pope, the bishop of Rome.
This succession is seen as necessary for maintaining the church's authenticity and preserving the original doctrines and practices as intended by Christ and his apostles. Without apostolic succession, the church would lose its historical connection to its founding figures, potentially compromising its spiritual authority and teachings. In contrast, some reformers, such as those during the Protestant Reformation, challenged this view by emphasizing the priesthood of all believers and downplaying the necessity of ordained clergy for sacraments in cases of necessity.