Hi
May I recommend Steve Allen on the Bible Religion and Morality Parts 1 and 2. These books look at the Bible from a unique moral perspective. Not only do they address the difficulty in reconciling the bloodthirsty God of the OT with the sweetness and light God of the NT but also shows that even the New Testament God isn't that much of a sweetheart either.The truth is most Christians, Jehovah's Witnesses included, don't care much for facts and historical documentation that discredits the Bible, but if you can show that the Bible is morally deficient, you may get them to take notice.
Another good one is Thomas Paine's The Age of Reason. Even after over 200 years since its initial publication, this book remains one of the most striking deconstructions of the Bible and organized religions ever printed.
All of these books are heavy-duty reading. If you want something light and humorous, yet in its own way thought provoking try Ken's Guide to the Bible by Ken Smith. All these books are available on Amazon
Happy Reading!
CyrusThePersian