On the first Pentecost, the Holy Spirit descended upon the Apostles, enabling them to proclaim the Gospel in various languages so the crowds could understand. As a result, 3,000 people were converted to Christianity on that day alone. This was the first act of a process called evangelization, in which, inspired and empowered by the Holy Spirit, individual members of the Church proclaim the core message of salvation through Jesus Christ, resulting in the conversion of more souls who then go out and continue to evangelize others. Evangelization is considered the fundamental mission of the Catholic Church because its goal is to guide all souls to heaven; therefore, it is the responsibility of every baptized Catholic to participate in this mission.