After working in youth and camping ministry in Winnipeg and Northwestern Ontario, Preston began his training for the priesthood in Berkeley California in 2001. After his ordinations in 2004 and 2005, Preston served as a hospital chaplain in Sacramento, California; not long after, he was appointed to St. Mary Magdalene, a multi-cultural parish in the south end of Winnipeg. In 2012, Preston moved to England, where he pursued a PhD in Christian Theology at the University of Cambridge, while serving as Priest Vicar at St. John’s College, and Director of Studies at Westminster College.
Preston moved to Waterloo in 2017 with his wife, Karen Sunabacka, who took a position as Associate Professor of Music at Conrad Grebel University College.