John,

"Missional" is often the description of people like Mark Driscoll and Tim Keller. Basically, they try to engage the culture by taking on the supposedly "non-sinful" parts of it. I don't know about Keller's ministry, but I can say that Driscoll's potty mouth is most assuredly sinful.

True godliness is a sincere feeling which loves God as Father as much as it fears and reverences Him as Lord, embraces His righteousness, and dreads offending Him worse than death~ Calvin