What feels like spiritual experience to believers could seem like psychosis, a break from reality, to another. Validating measures that discriminate spiritual experiences from psychopathology reduce iatrogenic effects of misdiagnosis. We tested the reliability and validity of the Spiritual Emergency Scale (SES), assessing internal consistency, test–retest reliability, structural, convergent, and divergent validity. The reliability and validity of the Experiences of Psychotic Symptoms Scale (EPSS) were tested to explore potential convergent and divergent relationships between SE and psychosis. Feedback from a spiritual pilot sample prompted scale amendments to the SES and EPSS, whereby 5-point Likert-type scales replaced true–false options. We sampled 98 people from online spiritual forums, 94 undergraduate psychology students, and 20 of their friends and family. Scales included the following: SE, positive symptoms of psychosis, alogia (disfluency of thought and speech), spirituality, depression, anxiety, stress, and mysticism (experiences of connectedness that escape language). The SES-R and EPSS-R exhibited good internal consistency and structural validity, adequate test–retest reliability, and convergent and divergent validity. SE emerges as a distinct measurable construct, overlapping with positive symptoms of psychosis, distinguishable from the negative dimension of psychosis by its divergent relationship with alogia.