Rev. Andrew Ong Chuan Leong was graduated from Berean Training (Bible) School with a diploma in 1971. He obtained his Bachelor of Biblical Studies degree in 1980 and Master of Arts degree in Far East Advanced School of Theology (now known as Asia Pacific Theological Seminary), Philippines. He also completed his Master of Ministry in Trinity Theological College, Singapore, in 1983. Now he is doing his doctoral studies with the Asia Graduate School of Theology.

He has been a pastor in three churches since 1968. He was a pioneering pastor in Bethel Assembly in Johore Bahru for four years (started pastoring while in Bible school), the Senior Pastor of Glad Tidings Assembly, Klang, for 5 years (1972-77) and Faith Assembly of God for more than 29 years since 15 August 1977.

He holds the Ordained Minister credentials with the Assemblies of God since 1974. He has served in the national level of the Assemblies of God of Singapore as Executive Committee and various positions such as the General Secretary and the Directors of various national departments including the principal post of the Assemblies of Bible College, in more than a quarter of a century. Presently, he is in charge of the Assembles of God of Singapore Archives and a member of the Management Committee of the Assemblies of God Bible College.

He has married Sis Elsie Yeo since 1972. He has two married daughters (Dinah Chin & Rev. Grace Cabusao, a missionary to Philippines), two sons-in-law (Jake Chin & Rev. Noel Cabusao), three grandsons (Darren, Denzel & Caleb) and a granddaughter (Kyla).