Allan has lived in several different cultures and has expertise in cross-cultural communication and acculturation studies, in particular in relation to migrant and humanitarian settlement. He has a strong interest in the early Church and older Christian movements, having lived and worked in the Middle East. His doctoral thesis explored the current state and future of the ancient Syriac Orthodox Church in diaspora in the West, in the context of ongoing conflicts in its countries of origin. He has also written on the Jacobite Syrian Orthodox Church (based in India). Allan teaches courses on Christians in leadership, Christian doctrine, and missions in Australia and overseas. A Spanish-speaker, he has taught Church History and Christ & Salvation and anchored other courses (including Spirit-Led Leadership and the Trinity & the Christian Life), for the Bogota, Colombia campus of Alphacrucis.

Prior to his doctoral studies, Allan had a 45 year career with the Australian Government, including diplomatic postings in Peru, Venezuela, Spain, Lebanon, Singapore and Kenya. He also worked extensively (in parallel) as an ordained Pentecostal Christian minister and local pastor.