When you replace your negative beliefs with positive ones, you can change the course of your life.
The first place to look for positive beliefs is in your faith. Then take a thorough look at all your blessings and charge your attitude with gratitude. This alone will fill you with enough positive momentum to change the course of your life.
Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy—think about such things.
Philippians 4:8 (NABRE)