As others have posted, you have no right to control another's beliefs.
You can talk to him if he is open to it about his beliefs, and how yours are different and why. That does not have to entail making him wrong. Be open. Hear him.

You have decided that your beliefs are right, and his are wrong. That is a surefire way to push him away. Encourage him to see the beauty in his religion, which may be what he is looking for.

Just as you want your own beliefs to be honored, his should also be honored. You don't want to push him into a defensive mode. No one deserves that.