The challenges of evangelization in the context of an increasingly urbanizedworld are marked by intense cultural, social, and religious transformations.Drawing from the documents of the Second Vatican Council, the Guidelines of theChurch in Brazil, and the orientations of Pope Francis, the work reflects on the needto return to the origins of the first Christian communities to reclaim the essence ofcommunal life and the transmission of faith. The formation of small missionaryecclesial communities emerges as an effective response to the complexities of citiesand their pluralistic culture. The research highlights that evangelizing urbancultures requires dialogue, creativity, and new languages, adapting to thecharacteristics and challenges of contemporary society. Urban culture,characterized by individualism, plurality, and a fast-paced rhythm, demands areconfiguration of pastoral action to promote solidarity and integration.Communities must act as spaces of welcome, integral formation, and missionarylife, reinforcing Christian identity and building bridges amidst social divisions. Theresearch emphasizes the importance of pastoral conversion as an indispensablerenewal for the success of the Church’s mission in urban environments. The Churchis called to transform the challenges of modernity into opportunities to renew itspresence and promote more just and fraternal coexistence, maintaining therelevance of the Gospel message in cities.