If we must have belief ?

Many people say : one should have belief , for it'll help he /her  to achieve more .

However , the facts as we can see , in a large number of the rich have no belief at all (especially in my country , China) . By the way , I wounder if it is a fault to be like that in westerners' opinion ?

Anyway , it excellent clear in my mind that belief sometime have the positive affects to one .

So , my question is : if we must have belief ?