Guilt and shame are emotions that, albeit subjectively negative, help humans adapt to their social environment. However, in some cases, there are pathogenic beliefs, shaped over the lifespan that sustain them and make them a source of psychopathological suffering. In this paper we will first briefly show how Control‐Mastery Theory (CMT) considers several types of pathogenic beliefs shaped by traumatic experiences that underly chronic feelings of guilt and shame. We then focus on a clinical case of Livia, a 28 year‐old woman with relational and academic problems suffering mainly from two such types of pathogenic beliefs: burdening guilt and disloyalty guilt. We describe how a) Livia was driven by adverse and traumatic experiences to form some of these pathogenic beliefs, b) how she tested the therapist in order to discover whether he would disconfirm these beliefs, and c) how the therapist was able to successfully pass these tests and provide her with new and healthier interpersonal experiences. The case of Livia will highlight therapists' ability to accurately formulate patients' goals, pathogenic beliefs—including types of guilt‐ and shame‐related beliefs—and traumas. Moreover, the case will illustrate how therapists can pass patients' tests and adopt the right attitude to help patients disprove their pathogenic beliefs and overcome problematic experiences of guilt and shame.