Here’s a short quote from Richard Rorty’s essay “Truth without Correspondence to Reality” for those who feel there is a tight link between politics and doctrine. Rorty uses the term “philosophy,” but I think the same argument holds true for philosophy, theology, or doctrine.
It is unfortunate, I think, that many people hope for a tighter link between philosophy and politics than there is or can be. In particular, people on the left keep hoping for a philosophical view which cannot be used by the political right, one which will lend itself only to good causes. But there never will be such a view; any philosophical view is a tool which can be used by many different hands.