Above all the Gospel must be proclaimed by witness. Take a Christian or a handful of Christians who, in the midst of their own community, show their capacity for understanding and acceptance, their sharing of life and destiny with other people, their solidarity with the efforts of all for whatever is noble and good. Let us suppose that, in addition, they radiate in an altogether simple and effective way their faith in values that go beyond current values, and their hope in something that is not seen and that one would not dare to imagine. Through this wordless witness these Christians stir up irresistible questions in the hearts of those who see how they live: Why are they like this? Why do they live in this way? What or who is it that inspires them? Why are they in our midst? Such a witness is already a silent proclamation of the Good News and a very powerful and effective one.
-Pope Paul VI, “On Evangelization in the Modern World”