Joshua is a devout Christian who converted from Hinduism during his college days. He graduated from Allahabad Agricultural Institute in November 1977. He went on to attend Prairie Bible Institute in Alberta, Canada for a 4-year degree program. After his graduation, he returned to India as State Director for Uttar Pradesh at Operation Mobilization India and served for 7 and a half years. On leaving OM in January 1994, he founded the Living Word Centre in Siliguri, where he trains young people in Bible and Vocational training. He also serves as the South Asia Director for Action International Ministries, with its HQ in Seattle, Washington. Joshua has also been leading the City Prayer Movement in Siliguri for the last 15 years and is an active senior Elder at his local church, Anugrah Mahima Mandali in Siliguri.