One possible version

Self-confidence is of great importance to us. We can achieve nothing without it. Madam Curie once said, “Life is not easy for any of us. We must work, and above all we must believe in ourselves.” With self-confidence supporting her, Madam Curie discovered the element radium and made great contributions to t he world. And this is true of many other scientists.

However, in our daily life there are many people who often complain that they lack the ability to do things well, but as a matter of fact, what they lack most is self-confidence. So anyone, no matter what he does, should have faith in himself. Only by having the right attitude towards one’s own ability and holding up faith in himself can he have the courage to work on and finally succeed.