Prior to retiring, he was the Professor Emeritus of Philosophical Theology and Head of the Department of Theology and Religious Studies at King's College London. He formerly taught philosophy at Trinity Western University in Langley, British Columbia and has written a book entitled "God, the Mind's Desire: Reference, Reason and Christian Thinking" published by Cambridge University Press. In 2004, Janz's first album "High Strung" was re-released on CD for the first time by Escape Music in the UK. More recently, he has launched a new brand, Transformation Theology, a re-make of Bonhoeffer's grass-root theology.