So if there are no denominations that have a dogma that says Mary was not a perpetual virgin, how come there are so many people in those denominations who teach it?
John MacArthur for example. Evangelical preacher whose study bible has sold more than a million copies, president of a seminary, pastor of a church, and considered to be one of the most popular evangelical preachers around. Actively teaches that Mary was not a perpetual virgin.
A simple google search will turn up site after site professing the Bible "truth" that Mary was not a virgin. Non-denominational churches, baptist churchs, evangelicals, church of Christ -- all teaching to their flocks that Mary was not a perpetual virgin.
Of course, they don't call it "dogma". They simply call it "biblical truth".
Come to think of it, they don't call anything "dogma".
It is interesting that one who claims 'no opinion' on a matter can so vehemently object when a group takes one side and defines it as being dogma, but has no objections to people teaching the other side at all, as long as they don't call it "dogma". They can call it "bible truth" though. Apparently that's okay.
Of course, the logic of that thinking escapes me.