The document of the International theological commission Theology today: Perspectives, Principles and Criteria in art. 21 speaks of “the truth of the gospel” (citing Gal 2:5) as to what theology is concerned with. The study investigates the significance of the phrase “the truth of the gospel” in the apostle Paul (occurring in his seven undisputed letters only in Gal 2:5 and 2:14) and in the document Theology today. Although the contexts are extremely different, both perspectives on this phrase are undoubtedly converging. Moreover, the understanding of “the truth of the gospel” by the apostle Paul can be an inspiration and encouragement for theology today.