From antiquity to the present, humanity’s sustained reflection on the afterlife and its attendant concerns has given rise to one of the most enduring narratives regarding humankind’s eschatological destiny. This narrative has been articulated across religious and ritual traditions in both textual and visual forms. The “Last Judgment” mural in Vank Cathedral, Isfahan—dating to the Safavid period and the premodern era of Islamic Iran—constitutes one such historical source, presenting a depiction of the Day of Resurrection grounded in Christian doctrine and its theological worldview. To read and interpret this visual narrative, the present study adopts a semiotic–semantic approach based on the Greimasian actantial discourse system. Through an analysis of the signs employed in this artistic work, the study seeks to elucidate the mechanisms of meaning production at play. The findings indicate that the signs—manifested through figures and other visual elements—assume diverse and multiple actantial roles within the mural’s discursive system. Through their interrelations and coordination, these signs collectively generate a semantic understanding of Heaven, Purgatory, and Hell, and by establishing visual and semantic unity across the overall structure of the artwork, they enable the reception and comprehension of a coherent narrative of the Day of Resurrection.