In recent decades, studies about cultural diplomacy and intercultural dialogue have advanced. But what is “cultural diplomacy”? We mean the practice of soft actions, which tends to determine collaborations among Authorities and different States. We can define the expression soft power as the possibility of building an action, a moderate will, which has the ability to ‘hold together cultures’. In this respect, we intend to dwell on the possibility of thinking of Jesus’ preaching as an original form of soft power. If we go back to the era and the vision of Judaism, we have the possibility of entering a system in which a hard power develops, a “strong power” of written laws, linked to the tradition of the Old Testament and, starting from the first century AD , a completely new form of power and its exercise, the powerless power of preaching, which will find its pioneers not only in Jesus, but also in John the Baptist.