Irenaeus of Lyon, a bishop who lived at the end of the second century and is recorded among the fathers of the Christian church, developed criteria for the understanding of biblical texts. These biblical texts were recognized as writings of divine revelation both by him and by contemporary Christian gnostic teachers with whose interpretations he was at variance. The Indian philosopher Sankara lived in an age closely resembling the European Early Middle Ages. He explained traditional texts of the Veda in a non-dualistic way that differed from other Hindu teachers thus presenting - like Irenaeus - a divine unity that transgresses all tensions. A comparison of the methods used by the two thinkers helps to understand both Christian and Hindu tradition. The author's aim is not primarily to establish differences but to invite dialogue.