Integrity and Having Fun

I have been struggling for over a year to convey to Crossroads the importance of a whole-life spirituality, a worshipping God in the everyday outlook.
A word that I think helpfully sums up this goal is 'integrity'. Not just in the sense of 'honest' or something, but in the sense of 'integrated'. This has been a helpful buzzword for the church, but I think we still have a long way to go.
So then I come across the values statement of the 'David Allen Company'. One of their values (they call them 'principles' and 'rules of engagement') is:

• We bring joyful engagement to our work and our lives (aka we have fun)

So then I start thinking. Perhaps John Piper is right in a whole other sense. Perhaps enjoying ourselves, or 'having fun' is the way we can make sure our lives are integrated. At the very least it is one clear proof that our lives are integrated.