Follow-Up to O'Reilly, the Bible and Gay Marriage

Tim Challies was very kind to post a link to my previous post on Bill O'Reilly, the Bible, and Gay Marriage.  One of his commenters brought up an objection that I thought I might respond to here.  I had written that without the Bible, the only moral consensus open to man is a wicked pagan idolatry.  The objection offered was that many people who do not accept the Bible nonetheless lead loving and moral lives.  We therefore can have morality without the Bible.  My answer is that while this is relatively true, my point pertained not to individual morality but the "moral consensus" of a society.  This is a different matter entirely.