Jehovah's Witnesses; the light becomes brighter......would you agree?

Are you immature in reading the Bible ? John chapter 6 verse 66 says that many left or abandoned Jesus because they found it repugnant that he said that unless they drank his blood and ate his flesh.They could not have eternal life. Jesus didn't try to prevent them from walking away. And talking about truths. Was God wrong in permitting polygamy within the Jewish nation? And later he changed that. Was he wrong in letting the Jews get divorced without their spouse committing adultery? And again later he changed that. In a sense the light of the truth was shining brighter and brighter,according to God's purpose.