As a child he was fascinated by films and the theatre and decided to make his career as an actor after his father took him to see Charlie Chaplin and Jackie Coogan in The Kid in 1921. After years in stage, film and television Whitehead struggled in the Hollywood Studio system, a pacifist in World War II and became dissatisfied with the roles he was given, and then first heard of the Bahá'í Faith in 1949. At his first informational meeting on the religion, Whitehead heard well-known researcher Marzieh Gail. Whitehead joined the religion late in 1950, gave public talks on the religion such as at World Religion Day observances and other occasions in the 1950s, went on pilgrimage to its spiritual and administrative center in Haifa in 1955. He also attended the first Bahá'í World Congress in 1963 in London. He then pioneered to Ireland while also taking to the Dublin theatrical opportunities. Whitehead was elected to the Local Spiritual Assembly of Dublin and the National Spiritual Assembly of Ireland on which he served for 15 years following its formation in 1972. From about 1973 through the end of his life Whitehead devoted much of his time to the concerns of the religion including work resulting in publishing three books collecting biographies of early Bahá'ís while in his 6th decade but he also supported the Irish Actors' Equity and the Screen Actors' Guild and served on the executive of the Irish branch of PEN, the international writers' club.