Ligon Duncan follows up to Mark Dever's post on egalitarianism by explaining why the issue of complementarianism vs. egalitarianism was warranted for inclusion in the Together for the Gospel statement:
(1) The denial of complementarianism undermines the church's practical embrace of the authority of Scripture (thus eventually and inevitably harming the church's witness to the Gospel).
(2) The church's confidence in the clarity of Scripture in undermined, because if you can get egalitarianism from the Bible, you can get anything from the Bible.
(3) Because the very ideal of equality championed by egalitarianism (whether secular or Christian) is a permutation of a particular strand of Enlightenment thought, and because this particular ideal of equality is actually alien to the biblical anthropology and ethic, whenever and wherever it is read into the text of Scripture and its principles are worked out consistently, there is a competition with a biblical view of manhood and womanhood.
(4) When the biblical distinctions of maleness and femaleness are denied, Christian discipleship is irretrievably damaged because there can be no talk of cultivating distinctively masculine Christian virtue or feminine Christian virtue.