Thank you for your testimony. Usually older people are tougher for changing their mind unless they are some really open-minded individuals, still even young people can be in denial phase for very long time. But don't worry, be patient with them and use prayers to break their blindness and wait until they are ready instead of repetitive arguing and you will see their eyes open much sooner. This mindset battle is not just factual but also very spiritual in the background and most people are really in pain before they are released to see. Be glad that you see because every exposed deception is giving you portion of freedom and is boosting your faith which is priceless.
RE: Message for Flat-Earthers