Why did sectarianism start?

Sectarianism often arises from historical, social, and political conflicts, particularly within religious or ethnic groups. It can be fueled by competition for power, resources, and identity, leading to deep-seated divisions. These tensions are often exacerbated by external influences, such as colonialism or state policies that favor one group over another. Over time, such divisions can become entrenched, resulting in cycles of mistrust and violence.