In 1953, plans for the In-Service Training Institute (ISTI) were launched as a result of the youth fellowship research committee spearheaded by H. B. Mitchell, Pansy Brown and Josie B. Green (Rogers). Harry B. Mitchell was the chairman of the Board of Christian Education for the National Association of the Church of God with Pansy Brown and Josie Rogers serving as officers for the youth fellowship.

Due to the lack of finances however, the plans were delayed until 1957. Through the vision of these two pioneering women, ISTI was born in July of 1957. Sponsored by the National Board of Christian Education, the purpose of ISTI was to train and develop leaders of the National Association throughout the country on an annual basis.

The first ISTI was held in Baltimore, Maryland at the Thomas Knox Business Institute. Thomas Knox was a member of the Baltimore Church of God where J. Sherman Scott was Pastor. The Baltimore congregation was very supportive and with a $50.00 donation from the Board of Christian Education of the National Association, ISTI was under way. Thirty-eight students attended this first ISTI at a cost of $25.00 per student which included tuition, lodging and board. Alta Greene, Thomas Sawyer, Wilbert Delaine, Clifton and Mary Morgan served as the first teachers of ISTI along with Pansy Brown. Pansy Brown was appointed as the first Director and Josie B. Rogers appointed as the first Dean. Since that time others who have held the position include:
   Mary F. Robinson, Dean (1965)
   Mary Boyd, Director (1968)
   Marcus H. Morgan, Director (1968)
   Rudolph Smith, Director (1971)

In 1972 the office of Dean and Director were combined and Rudolph Smith held both positions until 1974, when the Board of Christian Education again separated the office of director and dean.
   Michael D. Curry, Director (1992 – 1995)
   Verda Beach, Dean (1992 – 2002)
   Michael A. Smith, Director (1996 – 2008)
   Elsa Johnson Bass, Dean (2003 – Present)
   Darrell Hazard, Director (2008 – 2011)
   Joel A. Johnson, Director (2012 – Present)

From 1957-61 ISTI was held at Thomas Knox Business Institute in Baltimore, Maryland. Since 1961 ISTI has traveled around the country training, educating, developing and expanding the leadership base of the National Association. Some of the cities which have hosted ISTI are:
   1962 - Chicago, IL
   1963 - Detroit, MI
   1966 - Washington, DC
   1967 - Akron, OH
   1970 - Raleigh. NC
   1973 - Atlanta, GA
   1976 - Tugaloo, MS
   1977 - Atlanta, GA
   1979 - to present, Anderson, IN

Today ISTI continues to fulfill the vision of those pioneering women and men who had a trail-blazing spirit to equip and edify God's people to do the work of ministry.