Schism

A diagram showing how to tell if a Church is schismatic by Redeemed Zoomer

Schism in the Church occurs when members leave the institution without prompting.

Some of the first schisms in the Church include those of the Novatianist, Donatist and Nestorian sects. In modern times, schism often occurs due to political differences, which often involves orthodox conservative Christians leaving a perceivably Liberal Church. This leads to the abandonment of mainline institutions by conservatives, thus fostering more Theological Liberalism.

There is absolutely no Biblical justification for schism and many foundational Reformed writers railed against it, especially Samuel Rutherford.