Here’s the whole thing in a nutshell:
But this conviction has to be sustained by our own constantly renewed experience of savouring Christ’s friendship and his message. It is impossible to persevere in a fervent evangelization unless we are convinced from personal experience that it is not the same thing to have known Jesus as not to have known him, not the same thing to walk with him as to walk blindly, not the same thing to hear his word as not to know it, and not the same thing to contemplate him, to worship him, to find our peace in him, as not to. It is not the same thing to try to build the world with his Gospel as to try to do so by our own lights. We know well that with Jesus life becomes richer and that with him it is easier to find meaning in everything. This is why we evangelize. A true missionary, who never ceases to be a disciple, knows that Jesus walks with him, speaks to him, breathes with him, works with him. He senses Jesus alive with him in the midst of the missionary enterprise. Unless we see him present at the heart of our missionary commitment, our enthusiasm soon wanes and we are no longer sure of what it is that we are handing on; we lack vigour and passion. A person who is not convinced, enthusiastic, certain and in love, will convince nobody.