Rev. Liu specialized in the Spiritual practices and Theology of the Puritans when he studied at the Fuller Theological Seminary. Before answering the call to be a minister, he has worked as a social worker for years. He has been teaching at ABS since 1992, teaching subjects like Systematic Theology, Christian Spirituality, Pentecost and Charismatic Movement, Spiritual Experiences and Discernment, etc. He guided several Doctor of Ministry theses and Master of Theology theses, which include studying Eugene Peterson, Jonathan Edwards, Richard Baxter, Spiritual Mapping of George Otis Jr., Molinism and Whistleblowing Ethics, etc.