The bishops summarize what we do to evangelize, per Pope Paul VI's Evangelii Nuntiandi:
- live a life imbued with Christian virtues
- proclaim unceasingly that salvation is offered to all... through Christ
- preach hope in God's love for us
Likewise, evangelization is for two groups: those who have never learned about the Good News, and those who have fallen away from it. In between, there are the faithful - the second of three circumstances that John Paul II described. Those people should not stagnate, just because they don't need evangelization. They need to continue to grow, intellectually and spiritually. That is where catechesis comes in.
As we learn our faith, we're better able to express the hope of salvation through Jesus Christ. As we grow in our faith we witness more effectively to those around us who have never heard the Gospel or who have fallen away from it.