Lifestyle Evangelism at the Workplace?

Pastor John Piper addresses this brand of evangelism as it pertains to the Christian’s workplace,

Thinking that our work will glorify God when people do not even know we are Christians is like admiring and effective ad on TV that never mentions the product. People may be impressed but won’t know what to buy.

This quotation came from his his excellent book “Don’t Waste Your Life”.

I’m not sure that I’ve seen such an apt analogy as it pertains to this popular form of evangelism.