PHOTO BLOG: What is the 'Front Line' of the Gospel's Advance?

GLOBAL ADVANCE EXISTS TO EMPOWER FRONTLINE LEADERS TO BE CATALYSTS FOR THE FULFILLING OF THE GREAT COMMISSION.
— Global Advance Mission Statement

Around Global Advance we talk a lot about frontline leaders. But what do we mean by that phrase, exactly? What does it mean to serve on the front lines of the Great Commission?