W. H. Auden worked with Charles Williams on a collection of Poetry he edited for Oxford University Press. Many years after first meeting Williams, he would recall that interview in surprising terms and mark it as one of the events that led him to embrace the Christian faith:
'For the first time in my life, [I] felt myself in the presence of personal sanctity... I had met many good people before who made me feel ashamed of my own shortcomings but in the presence of this man... I did not feel ashamed. I felt transformed into a person who was incapable of doing or thinking anything base or unloving (I later discovered that he had had a similar effect on many other people.)'
From Auden's testimony "witnessing" can be more effective if it is a mode of being than a mode of soing or talking.