Expect it: People can sense the underlying attitude no matter what we say or do. Let them know you are expecting them to succeed.
Verbalize it: People need to hear it. Tell them to that you believe in them and want them to succeed. Become a positive prophet of their success.
Reinforce it: People need encouragement. Seeing that you care to know their progress will let them realize that is also important to you.
Pave the way: Give them opportunity to show their best. Give them challenge to harness their worth. Give the boost and helping hand.
Once people recognize and understand that you genuinely want them succeed and are committed to helping them, they will begin to believe that they can accomplish what you give to them.