 The family migrated to Busan, where Ahn grew up in the Haeundae District, the city in which he would later found his church.From 1937, during the Second Sino-Japanese War and World War II, Ahn and his mother lived in Japan over a nine-year period.He returned to Korea in 1946, after the war, and began attending the local congregation of the Seventh-day Adventist Church in Incheon in 1947.