One thing I run into a lot is theists asking if secularists don’t have God to stamp his authority on things being right and wrong, isn’t morality just whatever strikes your fancy, like Roman spectators cheering christians being fed to the lions, or cultural cannibalism, or Palestinians celebrating 9/11?
This issue is resolved somewhat when we think about how moral judgements are made and how we tell they are correct. It is not just “God says so,” but God also would have to assess and evaluates according to criteria. Be it judging a UFC fight or a fine wine, judging is made according to criteria. The criteria are reliable, as they have been tested and refined over the years. And, while it’s true not every judge is going to score a child’s narrative writing in the same way, we have fairly objective and reliable guidelines: The Six Traits of Writing are rooted in more than 50 years of research. This research reveals that all “good” writing has six key ingredients—ideas, organization, voice, word choice, sentence fluency, and conventions. Criteria are living entities in that we ever more closely try to approximate the ideal. In ethics, we currently look to the standard of Universal Human Rights.