A crisis of faith is a deep and painful questioning, loss, or transformation of belief. Commonly, the term is used in reference to a crisis of religious faith, such as doubt about the existence or doubt about the goodness of God, but it can also be used when faith in humanity, society, an institution, or belief in an ideology are in question, and it especially can be used when an interconnected web of beliefs is challenged. It may designate an individual's internal struggle with their own faith, or an era of collective struggle.