Olang' spent his early years in Kano, Kisumu District, where he acquired fluency in Luo and Luhyia.

Under his guidance, he taught Sunday school classes at the area and also encouraged planting trees near the village churches.

He moved to Alliance High School, in Kikuyu, in 1931, where he stayed until 1935, three years of this at secondary level and the remaining two in teacher training.

Olang' decided to study to become an Anglican priest, joining St. Paul's Divinity School, in Limuru, in January 1944.

Olang' and Obadiah Kariuki were consecrated the first two African assistant bishops in Kenya by the Archbishop of Canterbury, Geoffrey Fisher, at Namirembe Cathedral, in Kampala, Uganda, on 15 March 1955.

In December 1960, he was nominated bishop of the Diocese of Maseno, covering Nyanza and Western provinces, being installed in 1961 by Archbishop Leonard Beecher, at St. Stephen's Church, in Kisumu, later his Pro-Cathedral.

Shortly after the division of the province of East Africa in two new provinces, Kenya and Tanzania, Olang' was chosen to be the first African archbishop of the Anglican Church of Kenya and bishop of Nairobi, with his enthronement taking place at the All Saints Cathedral, in Nairobi, on 3 August 1970, in a ceremony presided by Archbishop Leonard Beecher.

[1] Olang' would serve as bishop-in-ordinary for the Armed Forces of Kenya and would held an ecclesiastical court for the discipline of the Kenyan clergy.

He worked to strengthen relationships with other members of the worldwide Anglican Communion, visiting several countries on behalf of the Church of the Province of Kenya, such as Great Britain, Germany, Canada, United States and Australia.

He preached peace, love, unity, and humility and hence was a great force in keeping the Anglican Church united during his tenure."