"The harvest is abundant but laborers are few. Ask the Master of the harvest to send more laborers for his harvest." These words of Jesus are usually referred to when we are reminded of the need to pray for more vocations to the priesthood and religious life. But these words of Jesus were spoken in the context of Jesus sending out not the 12 apostles but the 72 disciples. In other words, Jesus was giving the task of preaching not just to the religious leaders but to all of his disciples & followers. In fact, the role of the priest is to build up the people of the parish in order that they may go into the world in which they live & work & proclaim the Gospel.
That work, that labor, is what we call "evangelization." But it's kind of an unattractive word for Catholics. We may not even know what it means and we usually don't view it as something we want to do. It simply means to preach the Gospel, to spread the Word, to help draw people to Christ. The Jehovah Witnesses do this well (at least they do it faithfully). But we Catholics don't want to go door to door to talk about God. Here's a better way to define evangelization: "One beggar telling another beggar how to find bread." In other words, knowing that we have found something that gives us life, that keeps us going, that feeds us, we want others to find this thing to.
Pope St. John Paul II coined the term the "new evangelization." Before we can tell someone else how to find bread, we have to know how to find it ourselves. Before we can invite another to faith, we have to find faith ourselves. That's why we are at Mass every Sunday: to remember that God loves us, to let God feed us with his presence in the Eucharist so that once we have found the bread of life, we can tell other beggars how to find bread for themselves.