Garth Coppin became a Christian when he was 14 years of age.
He became the first treasurer of the Cape Town Baptist College before it changed its name to a Seminary. Garth was both a deacon and treasurer at the Claremont Baptist Church and the Honeyridge Baptist Church. He is a chartered accountant and was partner with the Big 4 accounting firm, Ernst & Young, for over 25 years. Professionally he was a member of the different bodies that set accounting and auditing standards in South Africa, as well as being a member of the Advisory Council to the body setting International Financial Reporting Standards. He is also a member of the Integrated Reporting Committee of South Africa.