John Graham Lake was born on 18 March 1870 in St Marys, Ontario, and raised in Michigan. By his thirties he ran a Chicago branch of the Wisconsin Central Insurance Company on a reported $50,000 annual salary — an extraordinary sum in 1906.
Following the 1906 Azusa Street revival and his own claimed healing under John Alexander Dowie's Zion City ministry, Lake liquidated his business and in April 1908 sailed for South Africa with his family and a small missionary party. Within five years the Apostolic Faith Mission of South Africa — which he co-founded with Thomas Hezmalhalch — claimed 625 congregations and 1,250 native preachers.
Lake returned to the United States in 1913 and settled in Spokane, Washington, where in 1915 he opened the Divine Healing Institute and its network of "Healing Rooms". Between 1915 and 1920 the Spokane city Better Business Bureau and the mayor's office logged over 100,000 recorded testimonies of healing — a claim documented in the 1920 civic proclamation naming Spokane "the healthiest city in the world".
He opened a second Healing Rooms operation in Portland in 1920 and continued speaking until his death on 16 September 1935. Cal Pierce reopened the Spokane Healing Rooms in 1999; there are now over 3,000 affiliated Healing Rooms in more than 90 countries.