Have you ever said or heard words "I believe that"? - It's the point where faith starts.
People who have faith in something or someone, usually, are happier and stronger. In any situation, they know what to do, regardless of life circumstances.
Faith is a state free of doubts. Try to imagine a life without them; it would be the most exciting life you could ever have. And there is only one step to this state - a decision to make. Let's do it together!
For example, make the decision to be happy for the next 5 minutes and observe how it will change your current state. It doesn't sound difficult, right?