The early Christian Church faced significant challenges in the form of heresies and schisms. Heresies were deviations from orthodox Christian beliefs and practises, whereas schisms were caused by disagreements over leadership and doctrine. These schisms resulted in the formation of rival Christian groups such as the Gnostics and the Montanists. Through councils such as the First Council of Nicaea, the Church responded by clarifying its teachings and consolidating its authority. The response of the early Church to these challenges shaped the development of Christian doctrine and Church organization for centuries to come.