The concept of takfir in Islam (in the context of belief and practise)

Takfir, which means accusing someone of being an infidel and expelling them from the Islamic framework, is one of the important terms in the science of theology (kalam). It has often been used to show the opponent as guilty and to exclude them. However, the science of theology attempts to define the boundaries and criteria of takfir. The internal conflicts that emerged towards the end of the Four Caliphs era paved the way for the emergence of many problems in the Islamic world, especially the issue of major sins. These problems created the need for distinguishing between faith and disbelief by various sects. Consequently, each theological sect defined faith and disbelief and declared those who did not conform to their definition of faith as infidels. In the early period of Islam, due to internal conflicts, takfir became a tool frequently used by each sect within the framework of their own views. Takfir undermined the unity and solidarity of Muslims and led to several problems. Declaring a Muslim an infidel, which means takfir, fuels violent religious interpretations and is thus a significant concept. Takfir appears in two forms: faith-based takfir and action-based takfir. Faith-based takfir is conducted on the basis of fundamental beliefs, while action-based takfir is directed towards behavior.