The "keep reading" defense of Biblical slavery is self-defeating.

"Don't let your modern ideals get in the way of understanding an ancient culture and a loving God."

This is moral relativism. You're saying morality was different then. That's the position you're arguing against.

The Bible doesn't merely describe slavery -- it prescribes it:

  Leviticus 25:44-46: "Your male and female slaves are to come from 
  the nations around you; from them you may buy slaves... You can 
  bequeath them to your children as inherited property and can make 
  them slaves for life."

If the Bible is your objective moral standard, then either:

  (a) Slavery is moral (defend this publicly)
  (b) You're bearing false witness about what the Bible says, 
      flagrantly breaking one of the ten commandments.

If you claim the New Testament supersedes Old Testament slavery rules, you've admitted morality changes over time. That's relativism. Case closed.

Re: "atheists don't understand the Bible" -- Pew Research (2010) tested this empirically. Results:

  Overall religious knowledge (32 questions):
  - Atheists/Agnostics: 20.9 correct
  - Jews: 20.5
  - Mormons: 20.3  
  - White Evangelicals: 17.6

Atheists scored #1 overall on religious knowledge, including Christianity-specific questions. The fastest path to atheism is reading the Bible cover to cover. Thank you for recommending it, you are putting more people on the path the atheism!

As an atheist who probably knows the bible even better than you do (and I can quote the parts about slavery and treating women like shit, and you're the one who misunderstands it, since you've just proven yourself by your own words to be an unwitting moral relativist), I vigorously endorse your recommendation that everyone should read the bible, since that's the best way to defeat it!

[1] https://www.pewresearch.org/religion/2010/09/28/u-s-religiou...