Believe you can and you're halfway there - Theodore Roosevelt.
Belief in yourself means having faith in your own capabilities. It means believing that you CAN do something — that it is within your ability.
When you believe in yourself, you can overcome self-doubt and have the confidence to take action and get things done.
One way to instill belief in the workplace is to buy motivational posters for the office. Surrounding yourself with inspirational quotes reinforces your belief.