In 1947, during the Whitby Conference of the International Missionary Council, John A. Mackay stated:

“The whole church must brace itself to face the frontier. That is to say, it must become a mobile missionary force, ready for a wilderness life. It must be ready to march towards the place where the real issues are and where the most crucial decisions must be made. It is a time for us all to be thinking of campaign tents rather than of cathedrals” (Renewal and Advance, edited by Ranson, p. 203). (Theology Today – Vol 23, No. 4 – January 1967)