Try listening to people you want to convince before trying to convince them. This approach doesn't have a 100% success rate, but it has a higher chance of success than your current approach has. The catch is you have to be open for them to convince you that your closely held beliefs are wrong. If you're not, and you dismiss everything they say out-of-hand, how can you expect them to be open to your ideas?
They cannot be convinced despite a plethora of opportunities given, not due to a lack of them. That's how I know quite well that they don't care about the truth. If you were to argue with these people you'd be eaten alive, as would anyone else.
This isn't chess, they make up the rules and knock over the pieces as they go. Again, no care for the truth. You cannot change that. The only thing we can do is outnumber them.
Just this week the local school cancelled a vaccination clinic because people believe covid isn't real and that the vaccine is there to put chips in you. That "the lord Jesus" is their immune system. These people will change the law from underneath you if you let them. They don't care about the truth.