Crisis of faith (วิกฤตศรัทธา) is a term commonly applied, especially in Western culture, to periods of intense doubt and internal conflict about one's preconceived beliefs or life decisions.
A crisis of faith can be contrasted to simply a period of doubt in that a crisis of faith demands reconciliation or reevaluation before one can continue believing in whichever tenet is in doubt or continuing in whatever life path is in question.