The purpose of this study is to examine evangelization in the Catholic Diocese of Moshi in the advent of social media in the 21st century. It investigates the use of social media among youth to find out what social media young people are using and how they are using it to share their faith. It explores the question of whether the use of social media among youth helps them actively in the use in their faith. A survey of 220 youth was conducted across four Vicariates of the Catholic Diocese of Moshi. The results show themajority of the sampled population use social media with Facebook (i.e., 84.44%) emerging as the leading source. Smartphones were the most popular device used by youth (i.e., 96%). The results suggest that the youth of the Diocese of Moshi access social media regularly and are using it for faith sharing (i.e., 90%). Apart from faith sharing, the youth surveyed interact with friends and families to explore politics, business, entertainment and education. Limitations of the research are provided and suggestions for further research are provided.