I think it’s really telling when a pastor’s bio on the back of a book promotes his blog, especially a site with a catchy title such as Raincitypastor.

Also from the back cover of O2,

Your physical body needs oxygen in order to survive.  Inhale, exhale… one leads naturally to the other. Inhale too long, and you feel as if your lungs will burst. Exhale too long, and you get light headed. The same rhythm is essential in the life of faith. You inhale life-giving strength from God through things like prayer, study, solitude, and silence. You exhale generosity, hospitality, and service to the poor. If you try to do one without the other, you won’t last very long.

Disclaimer: I received a free copy of this book.