Some persons cite harsh passages in the OT about genocidal “killing all the women and children” to discredit the Bible.  Even “dashing babies on the rocks” (Psalm 137:9) was a retribution some Babylonian exiles sang about and hoped for.  Christ took that “dashing” upon Himself on the cross.  You can cite other Psalms where a psalmist wished horrible things on his enemies.  This is not the final message of the recounted history of the OT.  The Son of David commanded that we love our enemies and lived what He preached when He laid down His life for His enemies.  Jesus said, “You have heard it said, but I say to you.”  In this He is the ultimate and final revelation of the God of the Bible.