He's been a "minister" as in a high government position (Minister for the Environment, Heritage and the Arts), not a pastor (that I am aware of).
He's active in Australian conservation, not conservative, circles. He's mostly a leftwing greenie, though he's discovered some pragmatism later in life and softened his views against the Australian/US military relationship and uranium mining.
He is a CHristian now, and has been attacked by green environmentalists as a sellout.