Indeed I would say that dialogue with other religions is a real form of evangelisation. It doesn’t mean you go into the conversation with a hidden agenda hoping that you will convert them all by the end of the dialogue – that would be a bit dishonest. But it means that you are showing and sharing the Christ in you, the truth in you, to them. This is also true of ecumenism. This is an important form of evangelisation as Christians from different churches relate to each other.
Christian Life in the Light of Christian Meditation 3: Evangelisation: by Laurence Freeman OSB