I detest all religions and my politics are generally way to the right of Margaret Thatcher's and a bit to the right of Adolph Hitler's. However my best friend is a fervent Roman Catholic (who never misses a church service, studies Theology to Masters degree level and beyond, and stays at Catholic retreats run by monks and nuns), as well as being a dedicated socialist.
Back in my teaching days, I was regional secretary of the non-striking Professional Association of Teachers (which was generally regarded as right-wing), a Maggie-worshipper and a dedicated atheist. My best friend was a member of the National Executive of the (left-wing) NAS/UWT, a socialist and a Methodist lay preacher.
It just makes for some interesting discussions ;-)