Changsub studied  at Briercrest Seminary between 2001-2005 and while there with his family, they visited a reserve near the schoool.  This is when God started preparing their hearts to return to Canada to work among the First Nations.  SIM Korea suggested they return to Canada and after two years of praying, felt convinced God had called them.

When they returned to Saskatchewan in 2009, they served the First Nations in Regina and surrounding areas.  They lead Bible studies, visited homes and mentored people.  In 2013, they moved to Prince Albert, SK to serve in three strategic ministries – Church planting, campus and prison ministry.