He continued his labourer job in Ivory Coast until he became a foreman. In 1913, he was unfortunately jailed in Ivory Coast for embezzlement.
Whiles in jail, he had an encounter with God through a dream instructing him to burn his fetishes. He resisted this and other admonitory experiences over several years before eventually accepting the call.
He later returned to the Gold Coast precisely Bompata in the Ashanti territory in 1917, where he began preaching and calling for the destruction of fetishes and abandonment of magic and witchcraft.
He later moved to Brong-Ahafo where he got a large following including chiefs and other traditional leaders.
“Whoever has ears, let them hear what the Spirit says to the churches. To the one who is victorious, I will give some of the hidden manna. I will also give that person a white stone with a new name written on it, known only to the one who receives it.”
Oppong wanted to work with the Basel missionaries but was rejected by the Basel missionaries (Presbyterian Church) several times because of his style of reading from a mystical stone suspecting his conversion until 1920 when he met a Wesleyan Methodist missionary, W. G. Waterworth, and traveled with him, and from then on Oppong worked with the Methodist church.
He brought a great impact to the Methodist church and baptized over 10,000 people and converted over 20,000 souls.
Oppong retired later and lived at his native village where he carried out his evangelistic outreaches in neighbouring villages. He later died in 1965.