Church has been a big part of his life from a very young age. He attended Canaan Church (an Assemblies of God church) in Kuala Lumpur, Malaysia from 1972 until his move to Australia, and was a lay leader at Canaan Church for many years.
He was doing insurance auditing for an insurance company in Malaysia for a few years before deciding to move to Australia to do some studies, which took him to Tasmania. While in Tasmania, he was involved in organizing an overseas student ministry for a few years when the Lord called him into full-time ministry.
He received his theological training at the Bible College of Victoria (BCV, now called Melbourne School of Theology) in Melbourne, Australia. Soon after his graduation in 1994, he went back to Kuala Lumpur, Malaysia to join his home church, Canaan Church, as their Associate Pastor.
He was assigned to provide pastoral oversight to Canaan Church’s new outreach in another part of Kuala Lumpur city in January 2000. Having set up the church there to self-support itself both financially and in personnel, Tham Fuan left the church in January 2002 to further his theological education, again at BCV, in a post-graduate program.
His time at BCV also saw him attending FGA Melbourne, which lasted for 4 years, including one year serving as a full-time pastor. He left FGA in 2006, and was soon invited to pastor Cornerstone Community Church (later called Cornerstone Church of Christ, after it's affiliation with Churches of Christ in Victorian and Tasmania). In September 2010, Cornerstone merged with International Christian Community (ICC), another Church of Christ, to form LifeGate Church of Christ.
Apart from his pastoral work in Malaysia, Tham Fuan was also a member of the Board of Directors of Wycliffe Malaysia (a missions agency) from 1996 to 2001, and was the Co-ordinator of the Central District Youth Department of the Assemblies of God of Malaysia for the term 1999/2000.