Born in Finland in 1918, Wahlstrom was commissioned as an officer in 1938. When World War II commenced, he was called up for military service and served as battalion chaplain for Finnish forces.
Wahlstrom served variously in pastoral, youth work, military chaplaincy, training and administrative roles in Canada, Europe and the United Kingdom. Aged 63, he was elected General on 23 October 1981 with 35 of 44 votes. He assumed command on 14 December.
Wahlstrom's activities included a visit to communist East Germany (from Berlin), and a six-day Holy Land Congress involving 1,500 delegates from 23 countries. Wahlstrom was known as the "Caring General" throughout his four-and-a-half years as General.
Wahlstrom retired in 1986 and died in 1999, age 81.