Heresy of the Week: Antidicomarianism

With Christmastide upon us (happy second day of Christmas and Feast Day of St. Stephen!), it seemed appropriate for this week's heresy to have something to do with the Nativity of Christ.  There are lots of "good" options, from denying the divinity of Christ to denying the virginal birth, etc., but my favorite heresy to say the name of won out.

Antidicomarianism is considered to be a sub-Apollinarianism heresy. By the 3rd century, it was considered an Orthodox teaching that Jesus’ siblings, mentioned in the Bible, were Joseph’s children from a previous marriage, or cousins. The Antidicomarianites, a word literally meaning “Adversaries of Mary”, taught that the brothers and sisters of Christ from the New Testament were actually the younger children of Mary and Joseph, born after Jesus. They were not, contrary to what the name implies, “against Mary”, but rather, were against the perpetual virginity of Mary. This thought was prevalent from the 3rd to 5th centuries and often considered a heresy, as it was found in the writings of known heretics Tertullian and Origen. Other Antidicomarianism heresies are Bonosianism, Helvidianism, and Jovinianism. Most protestant churches are Antidicomarianites, however in confessional Lutheranism, there seems to be a mix of Antidicomarianites and those who subscribe to the perpetual virginity of Mary.

A few brief notes on this one:

1. Until I started researching heresies earlier this year, I didn't actually know any Lutherans believed in the perpetual virginity of Mary.  I knew Luther held to that belief, but I was surprised to find out that many confessional Lutherans do as well, particularly Pastors.  I honestly never gave it much thought previously.  I don't fall one way or the other on this, and since it is an issue of adiphoria (not of doctrinal consequence or having effect on one's salvation), I don't feel a particular need to worry about it.  I think I tend to lean on the side of the Antidicomarianites, but as one Pastor I spoke to about this put it... why on earth would we care about the sex life of the mother of our Savior?
2. Because it doesn't affect salvation and is an issue of adiphoria, I don't know if this can be considered a heresy other than loosely (heresy meaning anything that departs from orthodoxy), but because it was condemned by the Roman Catholic Church as one, I've included it in my listings.
3. What would be a heresy and would affect salvation to some degree would be denying the virginal birth.  To be clear, Antidicomarianism doesn't do that.  Other heresies do.